diff --git a/contracts/access/access_control/AccessControlInternal.sol b/contracts/access/access_control/AccessControlInternal.sol
index ff147f25..82267a1f 100644
--- a/contracts/access/access_control/AccessControlInternal.sol
+++ b/contracts/access/access_control/AccessControlInternal.sol
@@ -33,7 +33,11 @@ abstract contract AccessControlInternal is IAccessControlInternal {
         address account
     ) internal view virtual returns (bool) {
         return
-            AccessControlStorage.layout().roles[role].members.contains(account);
+            AccessControlStorage
+                .layout(AccessControlStorage.DEFAULT_STORAGE_SLOT)
+                .roles[role]
+                .members
+                .contains(account);
     }
 
     /**
@@ -72,7 +76,11 @@ abstract contract AccessControlInternal is IAccessControlInternal {
     function _getRoleAdmin(
         bytes32 role
     ) internal view virtual returns (bytes32) {
-        return AccessControlStorage.layout().roles[role].adminRole;
+        return
+            AccessControlStorage
+                .layout(AccessControlStorage.DEFAULT_STORAGE_SLOT)
+                .roles[role]
+                .adminRole;
     }
 
     /**
@@ -82,7 +90,10 @@ abstract contract AccessControlInternal is IAccessControlInternal {
      */
     function _setRoleAdmin(bytes32 role, bytes32 adminRole) internal virtual {
         bytes32 previousAdminRole = _getRoleAdmin(role);
-        AccessControlStorage.layout().roles[role].adminRole = adminRole;
+        AccessControlStorage
+            .layout(AccessControlStorage.DEFAULT_STORAGE_SLOT)
+            .roles[role]
+            .adminRole = adminRole;
         emit RoleAdminChanged(role, previousAdminRole, adminRole);
     }
 
@@ -92,7 +103,11 @@ abstract contract AccessControlInternal is IAccessControlInternal {
      * @param account recipient of role assignment
      */
     function _grantRole(bytes32 role, address account) internal virtual {
-        AccessControlStorage.layout().roles[role].members.add(account);
+        AccessControlStorage
+            .layout(AccessControlStorage.DEFAULT_STORAGE_SLOT)
+            .roles[role]
+            .members
+            .add(account);
         emit RoleGranted(role, account, msg.sender);
     }
 
@@ -102,7 +117,11 @@ abstract contract AccessControlInternal is IAccessControlInternal {
      * @parm account
      */
     function _revokeRole(bytes32 role, address account) internal virtual {
-        AccessControlStorage.layout().roles[role].members.remove(account);
+        AccessControlStorage
+            .layout(AccessControlStorage.DEFAULT_STORAGE_SLOT)
+            .roles[role]
+            .members
+            .remove(account);
         emit RoleRevoked(role, account, msg.sender);
     }
 
@@ -123,7 +142,12 @@ abstract contract AccessControlInternal is IAccessControlInternal {
         bytes32 role,
         uint256 index
     ) internal view virtual returns (address) {
-        return AccessControlStorage.layout().roles[role].members.at(index);
+        return
+            AccessControlStorage
+                .layout(AccessControlStorage.DEFAULT_STORAGE_SLOT)
+                .roles[role]
+                .members
+                .at(index);
     }
 
     /**
@@ -133,6 +157,11 @@ abstract contract AccessControlInternal is IAccessControlInternal {
     function _getRoleMemberCount(
         bytes32 role
     ) internal view virtual returns (uint256) {
-        return AccessControlStorage.layout().roles[role].members.length();
+        return
+            AccessControlStorage
+                .layout(AccessControlStorage.DEFAULT_STORAGE_SLOT)
+                .roles[role]
+                .members
+                .length();
     }
 }
diff --git a/contracts/access/access_control/AccessControlStorage.sol b/contracts/access/access_control/AccessControlStorage.sol
index b1d5dd06..2f75b911 100644
--- a/contracts/access/access_control/AccessControlStorage.sol
+++ b/contracts/access/access_control/AccessControlStorage.sol
@@ -16,11 +16,22 @@ library AccessControlStorage {
 
     bytes32 internal constant DEFAULT_ADMIN_ROLE = 0x00;
 
-    bytes32 internal constant STORAGE_SLOT =
-        keccak256('solidstate.contracts.storage.AccessControl');
+    bytes32 internal constant DEFAULT_STORAGE_SLOT =
+        keccak256(
+            abi.encode(
+                uint256(
+                    keccak256(
+                        bytes('solidstate.contracts.storage.AccessControl')
+                    )
+                ) - 1
+            )
+        ) & ~bytes32(uint256(0xff));
 
     function layout() internal pure returns (Layout storage l) {
-        bytes32 slot = STORAGE_SLOT;
+        l = layout(DEFAULT_STORAGE_SLOT);
+    }
+
+    function layout(bytes32 slot) internal pure returns (Layout storage l) {
         assembly {
             l.slot := slot
         }
diff --git a/contracts/access/ownable/OwnableInternal.sol b/contracts/access/ownable/OwnableInternal.sol
index b702e0d1..dec7b1c6 100644
--- a/contracts/access/ownable/OwnableInternal.sol
+++ b/contracts/access/ownable/OwnableInternal.sol
@@ -22,7 +22,7 @@ abstract contract OwnableInternal is IOwnableInternal {
     }
 
     function _owner() internal view virtual returns (address) {
-        return OwnableStorage.layout().owner;
+        return OwnableStorage.layout(OwnableStorage.DEFAULT_STORAGE_SLOT).owner;
     }
 
     function _transitiveOwner() internal view virtual returns (address owner) {
@@ -42,7 +42,9 @@ abstract contract OwnableInternal is IOwnableInternal {
     }
 
     function _setOwner(address account) internal virtual {
-        OwnableStorage.Layout storage l = OwnableStorage.layout();
+        OwnableStorage.Layout storage l = OwnableStorage.layout(
+            OwnableStorage.DEFAULT_STORAGE_SLOT
+        );
         emit OwnershipTransferred(l.owner, account);
         l.owner = account;
     }
diff --git a/contracts/access/ownable/OwnableStorage.sol b/contracts/access/ownable/OwnableStorage.sol
index 7d999dc1..224a306f 100644
--- a/contracts/access/ownable/OwnableStorage.sol
+++ b/contracts/access/ownable/OwnableStorage.sol
@@ -7,11 +7,20 @@ library OwnableStorage {
         address owner;
     }
 
-    bytes32 internal constant STORAGE_SLOT =
-        keccak256('solidstate.contracts.storage.Ownable');
+    bytes32 internal constant DEFAULT_STORAGE_SLOT =
+        keccak256(
+            abi.encode(
+                uint256(
+                    keccak256(bytes('solidstate.contracts.storage.Ownable'))
+                ) - 1
+            )
+        ) & ~bytes32(uint256(0xff));
 
     function layout() internal pure returns (Layout storage l) {
-        bytes32 slot = STORAGE_SLOT;
+        l = layout(DEFAULT_STORAGE_SLOT);
+    }
+
+    function layout(bytes32 slot) internal pure returns (Layout storage l) {
         assembly {
             l.slot := slot
         }
diff --git a/contracts/access/ownable/SafeOwnableInternal.sol b/contracts/access/ownable/SafeOwnableInternal.sol
index ca10b580..60b1d04a 100644
--- a/contracts/access/ownable/SafeOwnableInternal.sol
+++ b/contracts/access/ownable/SafeOwnableInternal.sol
@@ -17,7 +17,10 @@ abstract contract SafeOwnableInternal is ISafeOwnableInternal, OwnableInternal {
      * @notice get the nominated owner who has permission to call acceptOwnership
      */
     function _nomineeOwner() internal view virtual returns (address) {
-        return SafeOwnableStorage.layout().nomineeOwner;
+        return
+            SafeOwnableStorage
+                .layout(SafeOwnableStorage.DEFAULT_STORAGE_SLOT)
+                .nomineeOwner;
     }
 
     /**
@@ -25,7 +28,9 @@ abstract contract SafeOwnableInternal is ISafeOwnableInternal, OwnableInternal {
      */
     function _acceptOwnership() internal virtual {
         _setOwner(msg.sender);
-        delete SafeOwnableStorage.layout().nomineeOwner;
+        delete SafeOwnableStorage
+            .layout(SafeOwnableStorage.DEFAULT_STORAGE_SLOT)
+            .nomineeOwner;
     }
 
     /**
@@ -39,6 +44,8 @@ abstract contract SafeOwnableInternal is ISafeOwnableInternal, OwnableInternal {
      * @notice set nominee owner
      */
     function _setNomineeOwner(address account) internal virtual {
-        SafeOwnableStorage.layout().nomineeOwner = account;
+        SafeOwnableStorage
+            .layout(SafeOwnableStorage.DEFAULT_STORAGE_SLOT)
+            .nomineeOwner = account;
     }
 }
diff --git a/contracts/access/ownable/SafeOwnableStorage.sol b/contracts/access/ownable/SafeOwnableStorage.sol
index 4664d57e..5847342b 100644
--- a/contracts/access/ownable/SafeOwnableStorage.sol
+++ b/contracts/access/ownable/SafeOwnableStorage.sol
@@ -7,11 +7,20 @@ library SafeOwnableStorage {
         address nomineeOwner;
     }
 
-    bytes32 internal constant STORAGE_SLOT =
-        keccak256('solidstate.contracts.storage.SafeOwnable');
+    bytes32 internal constant DEFAULT_STORAGE_SLOT =
+        keccak256(
+            abi.encode(
+                uint256(
+                    keccak256(bytes('solidstate.contracts.storage.SafeOwnable'))
+                ) - 1
+            )
+        ) & ~bytes32(uint256(0xff));
 
     function layout() internal pure returns (Layout storage l) {
-        bytes32 slot = STORAGE_SLOT;
+        l = layout(DEFAULT_STORAGE_SLOT);
+    }
+
+    function layout(bytes32 slot) internal pure returns (Layout storage l) {
         assembly {
             l.slot := slot
         }
diff --git a/contracts/introspection/ERC165/base/ERC165BaseInternal.sol b/contracts/introspection/ERC165/base/ERC165BaseInternal.sol
index 8ce45441..df2e8a90 100644
--- a/contracts/introspection/ERC165/base/ERC165BaseInternal.sol
+++ b/contracts/introspection/ERC165/base/ERC165BaseInternal.sol
@@ -17,7 +17,10 @@ abstract contract ERC165BaseInternal is IERC165BaseInternal {
     function _supportsInterface(
         bytes4 interfaceId
     ) internal view virtual returns (bool) {
-        return ERC165BaseStorage.layout().supportedInterfaces[interfaceId];
+        return
+            ERC165BaseStorage
+                .layout(ERC165BaseStorage.DEFAULT_STORAGE_SLOT)
+                .supportedInterfaces[interfaceId];
     }
 
     /**
@@ -30,6 +33,8 @@ abstract contract ERC165BaseInternal is IERC165BaseInternal {
         bool status
     ) internal virtual {
         if (interfaceId == 0xffffffff) revert ERC165Base__InvalidInterfaceId();
-        ERC165BaseStorage.layout().supportedInterfaces[interfaceId] = status;
+        ERC165BaseStorage
+            .layout(ERC165BaseStorage.DEFAULT_STORAGE_SLOT)
+            .supportedInterfaces[interfaceId] = status;
     }
 }
diff --git a/contracts/introspection/ERC165/base/ERC165BaseStorage.sol b/contracts/introspection/ERC165/base/ERC165BaseStorage.sol
index ee683530..7e335e7d 100644
--- a/contracts/introspection/ERC165/base/ERC165BaseStorage.sol
+++ b/contracts/introspection/ERC165/base/ERC165BaseStorage.sol
@@ -7,11 +7,20 @@ library ERC165BaseStorage {
         mapping(bytes4 => bool) supportedInterfaces;
     }
 
-    bytes32 internal constant STORAGE_SLOT =
-        keccak256('solidstate.contracts.storage.ERC165Base');
+    bytes32 internal constant DEFAULT_STORAGE_SLOT =
+        keccak256(
+            abi.encode(
+                uint256(
+                    keccak256(bytes('solidstate.contracts.storage.ERC165Base'))
+                ) - 1
+            )
+        ) & ~bytes32(uint256(0xff));
 
     function layout() internal pure returns (Layout storage l) {
-        bytes32 slot = STORAGE_SLOT;
+        l = layout(DEFAULT_STORAGE_SLOT);
+    }
+
+    function layout(bytes32 slot) internal pure returns (Layout storage l) {
         assembly {
             l.slot := slot
         }
diff --git a/contracts/multisig/ECDSAMultisigWalletInternal.sol b/contracts/multisig/ECDSAMultisigWalletInternal.sol
index ad5ece8f..b6fbf45d 100644
--- a/contracts/multisig/ECDSAMultisigWalletInternal.sol
+++ b/contracts/multisig/ECDSAMultisigWalletInternal.sol
@@ -19,16 +19,21 @@ abstract contract ECDSAMultisigWalletInternal is IECDSAMultisigWalletInternal {
         address account,
         uint256 nonce
     ) internal view returns (bool) {
-        return ECDSAMultisigWalletStorage.layout().nonces[account][nonce];
+        return
+            ECDSAMultisigWalletStorage
+                .layout(ECDSAMultisigWalletStorage.DEFAULT_STORAGE_SLOT)
+                .nonces[account][nonce];
     }
 
     function _setInvalidNonce(address account, uint256 nonce) internal {
-        ECDSAMultisigWalletStorage.layout().nonces[account][nonce] = true;
+        ECDSAMultisigWalletStorage
+            .layout(ECDSAMultisigWalletStorage.DEFAULT_STORAGE_SLOT)
+            .nonces[account][nonce] = true;
     }
 
     function _setQuorum(uint256 quorum) internal {
         ECDSAMultisigWalletStorage.Layout storage l = ECDSAMultisigWalletStorage
-            .layout();
+            .layout(ECDSAMultisigWalletStorage.DEFAULT_STORAGE_SLOT);
 
         if (quorum > l.signers.length())
             revert ECDSAMultisigWallet__InsufficientSigners();
@@ -36,12 +41,16 @@ abstract contract ECDSAMultisigWalletInternal is IECDSAMultisigWalletInternal {
     }
 
     function _isSigner(address account) internal view returns (bool) {
-        return ECDSAMultisigWalletStorage.layout().signers.contains(account);
+        return
+            ECDSAMultisigWalletStorage
+                .layout(ECDSAMultisigWalletStorage.DEFAULT_STORAGE_SLOT)
+                .signers
+                .contains(account);
     }
 
     function _addSigner(address account) internal {
         ECDSAMultisigWalletStorage.Layout storage l = ECDSAMultisigWalletStorage
-            .layout();
+            .layout(ECDSAMultisigWalletStorage.DEFAULT_STORAGE_SLOT);
 
         if (l.signers.length() >= 256)
             revert ECDSAMultisigWallet__SignerLimitReached();
@@ -51,7 +60,7 @@ abstract contract ECDSAMultisigWalletInternal is IECDSAMultisigWalletInternal {
 
     function _removeSigner(address account) internal {
         ECDSAMultisigWalletStorage.Layout storage l = ECDSAMultisigWalletStorage
-            .layout();
+            .layout(ECDSAMultisigWalletStorage.DEFAULT_STORAGE_SLOT);
 
         if (l.quorum > l.signers.length() - 1)
             revert ECDSAMultisigWallet__InsufficientSigners();
@@ -125,7 +134,7 @@ abstract contract ECDSAMultisigWalletInternal is IECDSAMultisigWalletInternal {
         Signature[] memory signatures
     ) internal virtual {
         ECDSAMultisigWalletStorage.Layout storage l = ECDSAMultisigWalletStorage
-            .layout();
+            .layout(ECDSAMultisigWalletStorage.DEFAULT_STORAGE_SLOT);
 
         if (l.quorum > signatures.length)
             revert ECDSAMultisigWallet__QuorumNotReached();
diff --git a/contracts/multisig/ECDSAMultisigWalletStorage.sol b/contracts/multisig/ECDSAMultisigWalletStorage.sol
index afec826e..406bf90c 100644
--- a/contracts/multisig/ECDSAMultisigWalletStorage.sol
+++ b/contracts/multisig/ECDSAMultisigWalletStorage.sol
@@ -11,11 +11,24 @@ library ECDSAMultisigWalletStorage {
         mapping(address => mapping(uint256 => bool)) nonces;
     }
 
-    bytes32 internal constant STORAGE_SLOT =
-        keccak256('solidstate.contracts.storage.ECDSAMultisigWallet');
+    bytes32 internal constant DEFAULT_STORAGE_SLOT =
+        keccak256(
+            abi.encode(
+                uint256(
+                    keccak256(
+                        bytes(
+                            'solidstate.contracts.storage.ECDSAMultisigWallet'
+                        )
+                    )
+                ) - 1
+            )
+        ) & ~bytes32(uint256(0xff));
 
     function layout() internal pure returns (Layout storage l) {
-        bytes32 slot = STORAGE_SLOT;
+        l = layout(DEFAULT_STORAGE_SLOT);
+    }
+
+    function layout(bytes32 slot) internal pure returns (Layout storage l) {
         assembly {
             l.slot := slot
         }
diff --git a/contracts/proxy/diamond/base/DiamondBase.sol b/contracts/proxy/diamond/base/DiamondBase.sol
index 5d9ea6ae..f400f6fb 100644
--- a/contracts/proxy/diamond/base/DiamondBase.sol
+++ b/contracts/proxy/diamond/base/DiamondBase.sol
@@ -24,7 +24,7 @@ abstract contract DiamondBase is IDiamondBase, Proxy {
     {
         // inline storage layout retrieval uses less gas
         DiamondBaseStorage.Layout storage l;
-        bytes32 slot = DiamondBaseStorage.STORAGE_SLOT;
+        bytes32 slot = DiamondBaseStorage.DEFAULT_STORAGE_SLOT;
         assembly {
             l.slot := slot
         }
diff --git a/contracts/proxy/diamond/base/DiamondBaseStorage.sol b/contracts/proxy/diamond/base/DiamondBaseStorage.sol
index 5496f514..734196a1 100644
--- a/contracts/proxy/diamond/base/DiamondBaseStorage.sol
+++ b/contracts/proxy/diamond/base/DiamondBaseStorage.sol
@@ -16,11 +16,20 @@ library DiamondBaseStorage {
         address fallbackAddress;
     }
 
-    bytes32 internal constant STORAGE_SLOT =
-        keccak256('solidstate.contracts.storage.DiamondBase');
+    bytes32 internal constant DEFAULT_STORAGE_SLOT =
+        keccak256(
+            abi.encode(
+                uint256(
+                    keccak256(bytes('solidstate.contracts.storage.DiamondBase'))
+                ) - 1
+            )
+        ) & ~bytes32(uint256(0xff));
 
     function layout() internal pure returns (Layout storage l) {
-        bytes32 slot = STORAGE_SLOT;
+        l = layout(DEFAULT_STORAGE_SLOT);
+    }
+
+    function layout(bytes32 slot) internal pure returns (Layout storage l) {
         assembly {
             l.slot := slot
         }
diff --git a/contracts/proxy/diamond/fallback/DiamondFallback.sol b/contracts/proxy/diamond/fallback/DiamondFallback.sol
index d92a0209..7f507f64 100644
--- a/contracts/proxy/diamond/fallback/DiamondFallback.sol
+++ b/contracts/proxy/diamond/fallback/DiamondFallback.sol
@@ -61,7 +61,9 @@ abstract contract DiamondFallback is
         virtual
         returns (address fallbackAddress)
     {
-        fallbackAddress = DiamondBaseStorage.layout().fallbackAddress;
+        fallbackAddress = DiamondBaseStorage
+            .layout(DiamondBaseStorage.DEFAULT_STORAGE_SLOT)
+            .fallbackAddress;
     }
 
     /**
@@ -69,6 +71,8 @@ abstract contract DiamondFallback is
      * @param fallbackAddress address of fallback implementation
      */
     function _setFallbackAddress(address fallbackAddress) internal virtual {
-        DiamondBaseStorage.layout().fallbackAddress = fallbackAddress;
+        DiamondBaseStorage
+            .layout(DiamondBaseStorage.DEFAULT_STORAGE_SLOT)
+            .fallbackAddress = fallbackAddress;
     }
 }
diff --git a/contracts/proxy/diamond/readable/DiamondReadableInternal.sol b/contracts/proxy/diamond/readable/DiamondReadableInternal.sol
index 5d61c94d..96bfa942 100644
--- a/contracts/proxy/diamond/readable/DiamondReadableInternal.sol
+++ b/contracts/proxy/diamond/readable/DiamondReadableInternal.sol
@@ -15,7 +15,9 @@ abstract contract DiamondReadableInternal is IDiamondReadableInternal {
      * @return diamondFacets array of structured facet data
      */
     function _facets() internal view returns (Facet[] memory diamondFacets) {
-        DiamondBaseStorage.Layout storage l = DiamondBaseStorage.layout();
+        DiamondBaseStorage.Layout storage l = DiamondBaseStorage.layout(
+            DiamondBaseStorage.DEFAULT_STORAGE_SLOT
+        );
 
         diamondFacets = new Facet[](l.selectorCount);
 
@@ -94,7 +96,9 @@ abstract contract DiamondReadableInternal is IDiamondReadableInternal {
     function _facetFunctionSelectors(
         address facet
     ) internal view returns (bytes4[] memory selectors) {
-        DiamondBaseStorage.Layout storage l = DiamondBaseStorage.layout();
+        DiamondBaseStorage.Layout storage l = DiamondBaseStorage.layout(
+            DiamondBaseStorage.DEFAULT_STORAGE_SLOT
+        );
 
         selectors = new bytes4[](l.selectorCount);
 
@@ -140,7 +144,9 @@ abstract contract DiamondReadableInternal is IDiamondReadableInternal {
         view
         returns (address[] memory addresses)
     {
-        DiamondBaseStorage.Layout storage l = DiamondBaseStorage.layout();
+        DiamondBaseStorage.Layout storage l = DiamondBaseStorage.layout(
+            DiamondBaseStorage.DEFAULT_STORAGE_SLOT
+        );
 
         addresses = new address[](l.selectorCount);
         uint256 numFacets;
@@ -195,6 +201,12 @@ abstract contract DiamondReadableInternal is IDiamondReadableInternal {
     function _facetAddress(
         bytes4 selector
     ) internal view returns (address facet) {
-        facet = address(bytes20(DiamondBaseStorage.layout().facets[selector]));
+        facet = address(
+            bytes20(
+                DiamondBaseStorage
+                    .layout(DiamondBaseStorage.DEFAULT_STORAGE_SLOT)
+                    .facets[selector]
+            )
+        );
     }
 }
diff --git a/contracts/proxy/diamond/writable/DiamondWritableInternal.sol b/contracts/proxy/diamond/writable/DiamondWritableInternal.sol
index 82d972dd..fa6f7552 100644
--- a/contracts/proxy/diamond/writable/DiamondWritableInternal.sol
+++ b/contracts/proxy/diamond/writable/DiamondWritableInternal.sol
@@ -25,7 +25,9 @@ abstract contract DiamondWritableInternal is IDiamondWritableInternal {
         address target,
         bytes memory data
     ) internal virtual {
-        DiamondBaseStorage.Layout storage l = DiamondBaseStorage.layout();
+        DiamondBaseStorage.Layout storage l = DiamondBaseStorage.layout(
+            DiamondBaseStorage.DEFAULT_STORAGE_SLOT
+        );
 
         unchecked {
             uint256 originalSelectorCount = l.selectorCount;
diff --git a/contracts/proxy/upgradeable/UpgradeableProxy.sol b/contracts/proxy/upgradeable/UpgradeableProxy.sol
index db6c11b2..fc48428c 100644
--- a/contracts/proxy/upgradeable/UpgradeableProxy.sol
+++ b/contracts/proxy/upgradeable/UpgradeableProxy.sol
@@ -16,7 +16,7 @@ abstract contract UpgradeableProxy is IUpgradeableProxy, Proxy {
     function _getImplementation() internal view override returns (address) {
         // inline storage layout retrieval uses less gas
         UpgradeableProxyStorage.Layout storage l;
-        bytes32 slot = UpgradeableProxyStorage.STORAGE_SLOT;
+        bytes32 slot = UpgradeableProxyStorage.DEFAULT_STORAGE_SLOT;
         assembly {
             l.slot := slot
         }
@@ -29,6 +29,8 @@ abstract contract UpgradeableProxy is IUpgradeableProxy, Proxy {
      * @param implementation implementation address
      */
     function _setImplementation(address implementation) internal {
-        UpgradeableProxyStorage.layout().implementation = implementation;
+        UpgradeableProxyStorage
+            .layout(UpgradeableProxyStorage.DEFAULT_STORAGE_SLOT)
+            .implementation = implementation;
     }
 }
diff --git a/contracts/proxy/upgradeable/UpgradeableProxyStorage.sol b/contracts/proxy/upgradeable/UpgradeableProxyStorage.sol
index 2719509e..fc628cca 100644
--- a/contracts/proxy/upgradeable/UpgradeableProxyStorage.sol
+++ b/contracts/proxy/upgradeable/UpgradeableProxyStorage.sol
@@ -7,11 +7,22 @@ library UpgradeableProxyStorage {
         address implementation;
     }
 
-    bytes32 internal constant STORAGE_SLOT =
-        keccak256('solidstate.contracts.storage.UpgradeableProxy');
+    bytes32 internal constant DEFAULT_STORAGE_SLOT =
+        keccak256(
+            abi.encode(
+                uint256(
+                    keccak256(
+                        bytes('solidstate.contracts.storage.UpgradeableProxy')
+                    )
+                ) - 1
+            )
+        ) & ~bytes32(uint256(0xff));
 
     function layout() internal pure returns (Layout storage l) {
-        bytes32 slot = STORAGE_SLOT;
+        l = layout(DEFAULT_STORAGE_SLOT);
+    }
+
+    function layout(bytes32 slot) internal pure returns (Layout storage l) {
         assembly {
             l.slot := slot
         }
diff --git a/contracts/security/initializable/InitializableInternal.sol b/contracts/security/initializable/InitializableInternal.sol
index 804efe15..6057ea72 100644
--- a/contracts/security/initializable/InitializableInternal.sol
+++ b/contracts/security/initializable/InitializableInternal.sol
@@ -21,7 +21,9 @@ abstract contract InitializableInternal is IInitializableInternal {
     }
 
     function _setInitializedVersion(uint8 version) internal virtual {
-        InitializableStorage.Layout storage l = InitializableStorage.layout();
+        InitializableStorage.Layout storage l = InitializableStorage.layout(
+            InitializableStorage.DEFAULT_STORAGE_SLOT
+        );
 
         if (l.initialized >= version)
             revert Initializable__AlreadyInitialized();
@@ -36,6 +38,8 @@ abstract contract InitializableInternal is IInitializableInternal {
         virtual
         returns (uint8 version)
     {
-        version = InitializableStorage.layout().initialized;
+        version = InitializableStorage
+            .layout(InitializableStorage.DEFAULT_STORAGE_SLOT)
+            .initialized;
     }
 }
diff --git a/contracts/security/initializable/InitializableStorage.sol b/contracts/security/initializable/InitializableStorage.sol
index feae6b33..4ebd0947 100644
--- a/contracts/security/initializable/InitializableStorage.sol
+++ b/contracts/security/initializable/InitializableStorage.sol
@@ -7,11 +7,22 @@ library InitializableStorage {
         uint8 initialized;
     }
 
-    bytes32 internal constant STORAGE_SLOT =
-        keccak256('solidstate.contracts.storage.Initializable');
+    bytes32 internal constant DEFAULT_STORAGE_SLOT =
+        keccak256(
+            abi.encode(
+                uint256(
+                    keccak256(
+                        bytes('solidstate.contracts.storage.Initializable')
+                    )
+                ) - 1
+            )
+        ) & ~bytes32(uint256(0xff));
 
     function layout() internal pure returns (Layout storage l) {
-        bytes32 slot = STORAGE_SLOT;
+        l = layout(DEFAULT_STORAGE_SLOT);
+    }
+
+    function layout(bytes32 slot) internal pure returns (Layout storage l) {
         assembly {
             l.slot := slot
         }
diff --git a/contracts/security/partially_pausable/PartiallyPausableInternal.sol b/contracts/security/partially_pausable/PartiallyPausableInternal.sol
index 4be92983..4bd76b3d 100644
--- a/contracts/security/partially_pausable/PartiallyPausableInternal.sol
+++ b/contracts/security/partially_pausable/PartiallyPausableInternal.sol
@@ -27,7 +27,9 @@ abstract contract PartiallyPausableInternal is IPartiallyPausableInternal {
     function _partiallyPaused(
         bytes32 key
     ) internal view virtual returns (bool status) {
-        status = PartiallyPausableStorage.layout().partiallyPaused[key];
+        status = PartiallyPausableStorage
+            .layout(PartiallyPausableStorage.DEFAULT_STORAGE_SLOT)
+            .partiallyPaused[key];
     }
 
     /**
@@ -37,7 +39,9 @@ abstract contract PartiallyPausableInternal is IPartiallyPausableInternal {
     function _partiallyPause(
         bytes32 key
     ) internal virtual whenNotPartiallyPaused(key) {
-        PartiallyPausableStorage.layout().partiallyPaused[key] = true;
+        PartiallyPausableStorage
+            .layout(PartiallyPausableStorage.DEFAULT_STORAGE_SLOT)
+            .partiallyPaused[key] = true;
         emit PartiallyPaused(msg.sender, key);
     }
 
@@ -48,7 +52,9 @@ abstract contract PartiallyPausableInternal is IPartiallyPausableInternal {
     function _partiallyUnpause(
         bytes32 key
     ) internal virtual whenPartiallyPaused(key) {
-        delete PartiallyPausableStorage.layout().partiallyPaused[key];
+        delete PartiallyPausableStorage
+            .layout(PartiallyPausableStorage.DEFAULT_STORAGE_SLOT)
+            .partiallyPaused[key];
         emit PartiallyUnpaused(msg.sender, key);
     }
 }
diff --git a/contracts/security/partially_pausable/PartiallyPausableStorage.sol b/contracts/security/partially_pausable/PartiallyPausableStorage.sol
index 6423659e..2d2f2e4a 100644
--- a/contracts/security/partially_pausable/PartiallyPausableStorage.sol
+++ b/contracts/security/partially_pausable/PartiallyPausableStorage.sol
@@ -7,11 +7,22 @@ library PartiallyPausableStorage {
         mapping(bytes32 => bool) partiallyPaused;
     }
 
-    bytes32 internal constant STORAGE_SLOT =
-        keccak256('solidstate.contracts.storage.PartiallyPausable');
+    bytes32 internal constant DEFAULT_STORAGE_SLOT =
+        keccak256(
+            abi.encode(
+                uint256(
+                    keccak256(
+                        bytes('solidstate.contracts.storage.PartiallyPausable')
+                    )
+                ) - 1
+            )
+        ) & ~bytes32(uint256(0xff));
 
     function layout() internal pure returns (Layout storage l) {
-        bytes32 slot = STORAGE_SLOT;
+        l = layout(DEFAULT_STORAGE_SLOT);
+    }
+
+    function layout(bytes32 slot) internal pure returns (Layout storage l) {
         assembly {
             l.slot := slot
         }
diff --git a/contracts/security/pausable/PausableInternal.sol b/contracts/security/pausable/PausableInternal.sol
index 468c9ded..3b075f7f 100644
--- a/contracts/security/pausable/PausableInternal.sol
+++ b/contracts/security/pausable/PausableInternal.sol
@@ -24,14 +24,18 @@ abstract contract PausableInternal is IPausableInternal {
      * @return status whether contract is paused
      */
     function _paused() internal view virtual returns (bool status) {
-        status = PausableStorage.layout().paused;
+        status = PausableStorage
+            .layout(PausableStorage.DEFAULT_STORAGE_SLOT)
+            .paused;
     }
 
     /**
      * @notice Triggers paused state, when contract is unpaused.
      */
     function _pause() internal virtual whenNotPaused {
-        PausableStorage.layout().paused = true;
+        PausableStorage
+            .layout(PausableStorage.DEFAULT_STORAGE_SLOT)
+            .paused = true;
         emit Paused(msg.sender);
     }
 
@@ -39,7 +43,9 @@ abstract contract PausableInternal is IPausableInternal {
      * @notice Triggers unpaused state, when contract is paused.
      */
     function _unpause() internal virtual whenPaused {
-        delete PausableStorage.layout().paused;
+        delete PausableStorage
+            .layout(PausableStorage.DEFAULT_STORAGE_SLOT)
+            .paused;
         emit Unpaused(msg.sender);
     }
 }
diff --git a/contracts/security/pausable/PausableStorage.sol b/contracts/security/pausable/PausableStorage.sol
index 39bdf795..ea4b0dc8 100644
--- a/contracts/security/pausable/PausableStorage.sol
+++ b/contracts/security/pausable/PausableStorage.sol
@@ -7,11 +7,20 @@ library PausableStorage {
         bool paused;
     }
 
-    bytes32 internal constant STORAGE_SLOT =
-        keccak256('solidstate.contracts.storage.Pausable');
+    bytes32 internal constant DEFAULT_STORAGE_SLOT =
+        keccak256(
+            abi.encode(
+                uint256(
+                    keccak256(bytes('solidstate.contracts.storage.Pausable'))
+                ) - 1
+            )
+        ) & ~bytes32(uint256(0xff));
 
     function layout() internal pure returns (Layout storage l) {
-        bytes32 slot = STORAGE_SLOT;
+        l = layout(DEFAULT_STORAGE_SLOT);
+    }
+
+    function layout(bytes32 slot) internal pure returns (Layout storage l) {
         assembly {
             l.slot := slot
         }
diff --git a/contracts/security/reentrancy_guard/ReentrancyGuard.sol b/contracts/security/reentrancy_guard/ReentrancyGuard.sol
index d3f51980..5debefcb 100644
--- a/contracts/security/reentrancy_guard/ReentrancyGuard.sol
+++ b/contracts/security/reentrancy_guard/ReentrancyGuard.sol
@@ -24,20 +24,26 @@ abstract contract ReentrancyGuard is IReentrancyGuard {
      */
     function _isReentrancyGuardLocked() internal view virtual returns (bool) {
         return
-            ReentrancyGuardStorage.layout().status == REENTRANCY_STATUS_LOCKED;
+            ReentrancyGuardStorage
+                .layout(ReentrancyGuardStorage.DEFAULT_STORAGE_SLOT)
+                .status == REENTRANCY_STATUS_LOCKED;
     }
 
     /**
      * @notice lock functions that use the nonReentrant modifier
      */
     function _lockReentrancyGuard() internal virtual {
-        ReentrancyGuardStorage.layout().status = REENTRANCY_STATUS_LOCKED;
+        ReentrancyGuardStorage
+            .layout(ReentrancyGuardStorage.DEFAULT_STORAGE_SLOT)
+            .status = REENTRANCY_STATUS_LOCKED;
     }
 
     /**
      * @notice unlock functions that use the nonReentrant modifier
      */
     function _unlockReentrancyGuard() internal virtual {
-        ReentrancyGuardStorage.layout().status = REENTRANCY_STATUS_UNLOCKED;
+        ReentrancyGuardStorage
+            .layout(ReentrancyGuardStorage.DEFAULT_STORAGE_SLOT)
+            .status = REENTRANCY_STATUS_UNLOCKED;
     }
 }
diff --git a/contracts/security/reentrancy_guard/ReentrancyGuardStorage.sol b/contracts/security/reentrancy_guard/ReentrancyGuardStorage.sol
index 87929c21..02061833 100644
--- a/contracts/security/reentrancy_guard/ReentrancyGuardStorage.sol
+++ b/contracts/security/reentrancy_guard/ReentrancyGuardStorage.sol
@@ -7,11 +7,22 @@ library ReentrancyGuardStorage {
         uint256 status;
     }
 
-    bytes32 internal constant STORAGE_SLOT =
-        keccak256('solidstate.contracts.storage.ReentrancyGuard');
+    bytes32 internal constant DEFAULT_STORAGE_SLOT =
+        keccak256(
+            abi.encode(
+                uint256(
+                    keccak256(
+                        bytes('solidstate.contracts.storage.ReentrancyGuard')
+                    )
+                ) - 1
+            )
+        ) & ~bytes32(uint256(0xff));
 
     function layout() internal pure returns (Layout storage l) {
-        bytes32 slot = STORAGE_SLOT;
+        l = layout(DEFAULT_STORAGE_SLOT);
+    }
+
+    function layout(bytes32 slot) internal pure returns (Layout storage l) {
         assembly {
             l.slot := slot
         }
diff --git a/contracts/signature/base/ERC1271Base.sol b/contracts/signature/ERC1271/base/ERC1271Base.sol
similarity index 90%
rename from contracts/signature/base/ERC1271Base.sol
rename to contracts/signature/ERC1271/base/ERC1271Base.sol
index 15826e8b..c6a34d4a 100644
--- a/contracts/signature/base/ERC1271Base.sol
+++ b/contracts/signature/ERC1271/base/ERC1271Base.sol
@@ -2,7 +2,7 @@
 
 pragma solidity ^0.8.20;
 
-import { IERC1271 } from '../../interfaces/IERC1271.sol';
+import { IERC1271 } from '../../../interfaces/IERC1271.sol';
 import { IERC1271Base } from './IERC1271Base.sol';
 import { ERC1271BaseInternal } from './ERC1271BaseInternal.sol';
 
diff --git a/contracts/signature/base/ERC1271BaseInternal.sol b/contracts/signature/ERC1271/base/ERC1271BaseInternal.sol
similarity index 91%
rename from contracts/signature/base/ERC1271BaseInternal.sol
rename to contracts/signature/ERC1271/base/ERC1271BaseInternal.sol
index 537d1111..0cad9ffb 100644
--- a/contracts/signature/base/ERC1271BaseInternal.sol
+++ b/contracts/signature/ERC1271/base/ERC1271BaseInternal.sol
@@ -2,7 +2,7 @@
 
 pragma solidity ^0.8.20;
 
-import { IERC1271 } from '../../interfaces/IERC1271.sol';
+import { IERC1271 } from '../../../interfaces/IERC1271.sol';
 
 /**
  * @title ERC1271Base internal functions
diff --git a/contracts/signature/base/IERC1271Base.sol b/contracts/signature/ERC1271/base/IERC1271Base.sol
similarity index 61%
rename from contracts/signature/base/IERC1271Base.sol
rename to contracts/signature/ERC1271/base/IERC1271Base.sol
index b319155a..c39b41e4 100644
--- a/contracts/signature/base/IERC1271Base.sol
+++ b/contracts/signature/ERC1271/base/IERC1271Base.sol
@@ -2,6 +2,6 @@
 
 pragma solidity ^0.8.20;
 
-import { IERC1271 } from '../../interfaces/IERC1271.sol';
+import { IERC1271 } from '../../../interfaces/IERC1271.sol';
 
 interface IERC1271Base is IERC1271 {}
diff --git a/contracts/signature/ownable/ERC1271Ownable.sol b/contracts/signature/ERC1271/ownable/ERC1271Ownable.sol
similarity index 100%
rename from contracts/signature/ownable/ERC1271Ownable.sol
rename to contracts/signature/ERC1271/ownable/ERC1271Ownable.sol
diff --git a/contracts/signature/ownable/ERC1271OwnableInternal.sol b/contracts/signature/ERC1271/ownable/ERC1271OwnableInternal.sol
similarity index 84%
rename from contracts/signature/ownable/ERC1271OwnableInternal.sol
rename to contracts/signature/ERC1271/ownable/ERC1271OwnableInternal.sol
index 69769902..46d453e3 100644
--- a/contracts/signature/ownable/ERC1271OwnableInternal.sol
+++ b/contracts/signature/ERC1271/ownable/ERC1271OwnableInternal.sol
@@ -2,8 +2,8 @@
 
 pragma solidity ^0.8.20;
 
-import { OwnableInternal } from '../../access/ownable/OwnableInternal.sol';
-import { ECDSA } from '../../cryptography/ECDSA.sol';
+import { OwnableInternal } from '../../../access/ownable/OwnableInternal.sol';
+import { ECDSA } from '../../../cryptography/ECDSA.sol';
 import { ERC1271BaseInternal } from '../base/ERC1271BaseInternal.sol';
 
 /**
diff --git a/contracts/signature/ownable/ERC1271OwnableMock.sol b/contracts/signature/ERC1271/ownable/ERC1271OwnableMock.sol
similarity index 100%
rename from contracts/signature/ownable/ERC1271OwnableMock.sol
rename to contracts/signature/ERC1271/ownable/ERC1271OwnableMock.sol
diff --git a/contracts/signature/ownable/IERC1271Ownable.sol b/contracts/signature/ERC1271/ownable/IERC1271Ownable.sol
similarity index 100%
rename from contracts/signature/ownable/IERC1271Ownable.sol
rename to contracts/signature/ERC1271/ownable/IERC1271Ownable.sol
diff --git a/contracts/signature/stored/ERC1271Stored.sol b/contracts/signature/ERC1271/stored/ERC1271Stored.sol
similarity index 100%
rename from contracts/signature/stored/ERC1271Stored.sol
rename to contracts/signature/ERC1271/stored/ERC1271Stored.sol
diff --git a/contracts/signature/stored/ERC1271StoredInternal.sol b/contracts/signature/ERC1271/stored/ERC1271StoredInternal.sol
similarity index 70%
rename from contracts/signature/stored/ERC1271StoredInternal.sol
rename to contracts/signature/ERC1271/stored/ERC1271StoredInternal.sol
index 3b393095..54de6f5f 100644
--- a/contracts/signature/stored/ERC1271StoredInternal.sol
+++ b/contracts/signature/ERC1271/stored/ERC1271StoredInternal.sol
@@ -14,12 +14,16 @@ abstract contract ERC1271StoredInternal is ERC1271BaseInternal {
         bytes memory
     ) internal view virtual override returns (bytes4 magicValue) {
         return
-            ERC1271StoredStorage.layout().hashes[hash]
+            ERC1271StoredStorage
+                .layout(ERC1271StoredStorage.DEFAULT_STORAGE_SLOT)
+                .hashes[hash]
                 ? MAGIC_VALUE
                 : bytes4(0);
     }
 
     function _setValidSignature(bytes32 hash, bool status) internal {
-        ERC1271StoredStorage.layout().hashes[hash] = status;
+        ERC1271StoredStorage
+            .layout(ERC1271StoredStorage.DEFAULT_STORAGE_SLOT)
+            .hashes[hash] = status;
     }
 }
diff --git a/contracts/signature/stored/ERC1271StoredMock.sol b/contracts/signature/ERC1271/stored/ERC1271StoredMock.sol
similarity index 81%
rename from contracts/signature/stored/ERC1271StoredMock.sol
rename to contracts/signature/ERC1271/stored/ERC1271StoredMock.sol
index 3fc90f9d..5784580e 100644
--- a/contracts/signature/stored/ERC1271StoredMock.sol
+++ b/contracts/signature/ERC1271/stored/ERC1271StoredMock.sol
@@ -7,7 +7,9 @@ import { ERC1271Stored } from './ERC1271Stored.sol';
 
 contract ERC1271StoredMock is ERC1271Stored {
     constructor(bytes32 hash) {
-        ERC1271StoredStorage.layout().hashes[hash] = true;
+        ERC1271StoredStorage
+            .layout(ERC1271StoredStorage.DEFAULT_STORAGE_SLOT)
+            .hashes[hash] = true;
     }
 
     function __isValidSignature(
diff --git a/contracts/signature/ERC1271/stored/ERC1271StoredStorage.sol b/contracts/signature/ERC1271/stored/ERC1271StoredStorage.sol
new file mode 100644
index 00000000..9c2b4a3e
--- /dev/null
+++ b/contracts/signature/ERC1271/stored/ERC1271StoredStorage.sol
@@ -0,0 +1,30 @@
+// SPDX-License-Identifier: MIT
+
+pragma solidity ^0.8.20;
+
+library ERC1271StoredStorage {
+    struct Layout {
+        mapping(bytes32 => bool) hashes;
+    }
+
+    bytes32 internal constant DEFAULT_STORAGE_SLOT =
+        keccak256(
+            abi.encode(
+                uint256(
+                    keccak256(
+                        bytes('solidstate.contracts.storage.ERC1271Stored')
+                    )
+                ) - 1
+            )
+        ) & ~bytes32(uint256(0xff));
+
+    function layout() internal pure returns (Layout storage l) {
+        l = layout(DEFAULT_STORAGE_SLOT);
+    }
+
+    function layout(bytes32 slot) internal pure returns (Layout storage l) {
+        assembly {
+            l.slot := slot
+        }
+    }
+}
diff --git a/contracts/signature/stored/IERC1271Stored.sol b/contracts/signature/ERC1271/stored/IERC1271Stored.sol
similarity index 100%
rename from contracts/signature/stored/IERC1271Stored.sol
rename to contracts/signature/ERC1271/stored/IERC1271Stored.sol
diff --git a/contracts/signature/ERC7201/ERC7201.sol b/contracts/signature/ERC7201/ERC7201.sol
new file mode 100644
index 00000000..ed195a24
--- /dev/null
+++ b/contracts/signature/ERC7201/ERC7201.sol
@@ -0,0 +1,22 @@
+// SPDX-License-Identifier: MIT
+
+pragma solidity ^0.8.20;
+
+/**
+ * @title EIP-7201 namespaced storage layout library
+ * @dev see https://eips.ethereum.org/EIPS/eip-7201
+ */
+library ERC7201 {
+    /**
+     * @notice calculate the EIP-7201 storage slot for a given string id
+     * @dev id parameter should not contain whitespace
+     * @param id namespace id
+     */
+    function calculateStorageSlot(
+        string memory id
+    ) internal pure returns (bytes32 slot) {
+        slot =
+            keccak256(abi.encode(uint256(keccak256(bytes(id))) - 1)) &
+            ~bytes32(uint256(0xff));
+    }
+}
diff --git a/contracts/signature/ERC7201/ERC7201Mock.sol b/contracts/signature/ERC7201/ERC7201Mock.sol
new file mode 100644
index 00000000..667df2a9
--- /dev/null
+++ b/contracts/signature/ERC7201/ERC7201Mock.sol
@@ -0,0 +1,13 @@
+// SPDX-License-Identifier: MIT
+
+pragma solidity ^0.8.20;
+
+import { ERC7201 } from './ERC7201.sol';
+
+contract ERC7201Mock {
+    function calculateStorageSlot(
+        string calldata id
+    ) external pure returns (bytes32 slot) {
+        slot = ERC7201.calculateStorageSlot(id);
+    }
+}
diff --git a/contracts/signature/stored/ERC1271StoredStorage.sol b/contracts/signature/stored/ERC1271StoredStorage.sol
deleted file mode 100644
index 7ce41d18..00000000
--- a/contracts/signature/stored/ERC1271StoredStorage.sol
+++ /dev/null
@@ -1,19 +0,0 @@
-// SPDX-License-Identifier: MIT
-
-pragma solidity ^0.8.20;
-
-library ERC1271StoredStorage {
-    struct Layout {
-        mapping(bytes32 => bool) hashes;
-    }
-
-    bytes32 internal constant STORAGE_SLOT =
-        keccak256('solidstate.contracts.storage.ERC1271Stored');
-
-    function layout() internal pure returns (Layout storage l) {
-        bytes32 slot = STORAGE_SLOT;
-        assembly {
-            l.slot := slot
-        }
-    }
-}
diff --git a/contracts/token/ERC1155/base/ERC1155Base.sol b/contracts/token/ERC1155/base/ERC1155Base.sol
index bc6069e9..44be7c50 100644
--- a/contracts/token/ERC1155/base/ERC1155Base.sol
+++ b/contracts/token/ERC1155/base/ERC1155Base.sol
@@ -34,7 +34,9 @@ abstract contract ERC1155Base is IERC1155Base, ERC1155BaseInternal {
             revert ERC1155Base__ArrayLengthMismatch();
 
         mapping(uint256 => mapping(address => uint256))
-            storage balances = ERC1155BaseStorage.layout().balances;
+            storage balances = ERC1155BaseStorage
+                .layout(ERC1155BaseStorage.DEFAULT_STORAGE_SLOT)
+                .balances;
 
         uint256[] memory batchBalances = new uint256[](accounts.length);
 
@@ -56,7 +58,10 @@ abstract contract ERC1155Base is IERC1155Base, ERC1155BaseInternal {
         address account,
         address operator
     ) public view virtual returns (bool) {
-        return ERC1155BaseStorage.layout().operatorApprovals[account][operator];
+        return
+            ERC1155BaseStorage
+                .layout(ERC1155BaseStorage.DEFAULT_STORAGE_SLOT)
+                .operatorApprovals[account][operator];
     }
 
     /**
@@ -64,9 +69,9 @@ abstract contract ERC1155Base is IERC1155Base, ERC1155BaseInternal {
      */
     function setApprovalForAll(address operator, bool status) public virtual {
         if (msg.sender == operator) revert ERC1155Base__SelfApproval();
-        ERC1155BaseStorage.layout().operatorApprovals[msg.sender][
-            operator
-        ] = status;
+        ERC1155BaseStorage
+            .layout(ERC1155BaseStorage.DEFAULT_STORAGE_SLOT)
+            .operatorApprovals[msg.sender][operator] = status;
         emit ApprovalForAll(msg.sender, operator, status);
     }
 
diff --git a/contracts/token/ERC1155/base/ERC1155BaseInternal.sol b/contracts/token/ERC1155/base/ERC1155BaseInternal.sol
index 8dbba8ff..caadd04b 100644
--- a/contracts/token/ERC1155/base/ERC1155BaseInternal.sol
+++ b/contracts/token/ERC1155/base/ERC1155BaseInternal.sol
@@ -26,7 +26,10 @@ abstract contract ERC1155BaseInternal is IERC1155BaseInternal {
     ) internal view virtual returns (uint256) {
         if (account == address(0))
             revert ERC1155Base__BalanceQueryZeroAddress();
-        return ERC1155BaseStorage.layout().balances[id][account];
+        return
+            ERC1155BaseStorage
+                .layout(ERC1155BaseStorage.DEFAULT_STORAGE_SLOT)
+                .balances[id][account];
     }
 
     /**
@@ -54,7 +57,9 @@ abstract contract ERC1155BaseInternal is IERC1155BaseInternal {
             data
         );
 
-        ERC1155BaseStorage.layout().balances[id][account] += amount;
+        ERC1155BaseStorage
+            .layout(ERC1155BaseStorage.DEFAULT_STORAGE_SLOT)
+            .balances[id][account] += amount;
 
         emit TransferSingle(msg.sender, address(0), account, id, amount);
     }
@@ -112,7 +117,9 @@ abstract contract ERC1155BaseInternal is IERC1155BaseInternal {
         );
 
         mapping(uint256 => mapping(address => uint256))
-            storage balances = ERC1155BaseStorage.layout().balances;
+            storage balances = ERC1155BaseStorage
+                .layout(ERC1155BaseStorage.DEFAULT_STORAGE_SLOT)
+                .balances;
 
         for (uint256 i; i < ids.length; ) {
             balances[ids[i]][account] += amounts[i];
@@ -172,7 +179,7 @@ abstract contract ERC1155BaseInternal is IERC1155BaseInternal {
         );
 
         mapping(address => uint256) storage balances = ERC1155BaseStorage
-            .layout()
+            .layout(ERC1155BaseStorage.DEFAULT_STORAGE_SLOT)
             .balances[id];
 
         unchecked {
@@ -202,7 +209,9 @@ abstract contract ERC1155BaseInternal is IERC1155BaseInternal {
         _beforeTokenTransfer(msg.sender, account, address(0), ids, amounts, '');
 
         mapping(uint256 => mapping(address => uint256))
-            storage balances = ERC1155BaseStorage.layout().balances;
+            storage balances = ERC1155BaseStorage
+                .layout(ERC1155BaseStorage.DEFAULT_STORAGE_SLOT)
+                .balances;
 
         unchecked {
             for (uint256 i; i < ids.length; i++) {
@@ -247,7 +256,9 @@ abstract contract ERC1155BaseInternal is IERC1155BaseInternal {
         );
 
         mapping(uint256 => mapping(address => uint256))
-            storage balances = ERC1155BaseStorage.layout().balances;
+            storage balances = ERC1155BaseStorage
+                .layout(ERC1155BaseStorage.DEFAULT_STORAGE_SLOT)
+                .balances;
 
         unchecked {
             uint256 senderBalance = balances[id][sender];
@@ -316,7 +327,9 @@ abstract contract ERC1155BaseInternal is IERC1155BaseInternal {
         _beforeTokenTransfer(operator, sender, recipient, ids, amounts, data);
 
         mapping(uint256 => mapping(address => uint256))
-            storage balances = ERC1155BaseStorage.layout().balances;
+            storage balances = ERC1155BaseStorage
+                .layout(ERC1155BaseStorage.DEFAULT_STORAGE_SLOT)
+                .balances;
 
         for (uint256 i; i < ids.length; ) {
             uint256 token = ids[i];
diff --git a/contracts/token/ERC1155/base/ERC1155BaseStorage.sol b/contracts/token/ERC1155/base/ERC1155BaseStorage.sol
index de355743..3ca70126 100644
--- a/contracts/token/ERC1155/base/ERC1155BaseStorage.sol
+++ b/contracts/token/ERC1155/base/ERC1155BaseStorage.sol
@@ -8,11 +8,20 @@ library ERC1155BaseStorage {
         mapping(address => mapping(address => bool)) operatorApprovals;
     }
 
-    bytes32 internal constant STORAGE_SLOT =
-        keccak256('solidstate.contracts.storage.ERC1155Base');
+    bytes32 internal constant DEFAULT_STORAGE_SLOT =
+        keccak256(
+            abi.encode(
+                uint256(
+                    keccak256(bytes('solidstate.contracts.storage.ERC1155Base'))
+                ) - 1
+            )
+        ) & ~bytes32(uint256(0xff));
 
     function layout() internal pure returns (Layout storage l) {
-        bytes32 slot = STORAGE_SLOT;
+        l = layout(DEFAULT_STORAGE_SLOT);
+    }
+
+    function layout(bytes32 slot) internal pure returns (Layout storage l) {
         assembly {
             l.slot := slot
         }
diff --git a/contracts/token/ERC1155/enumerable/ERC1155EnumerableInternal.sol b/contracts/token/ERC1155/enumerable/ERC1155EnumerableInternal.sol
index 2a9fee73..e5d5fc3f 100644
--- a/contracts/token/ERC1155/enumerable/ERC1155EnumerableInternal.sol
+++ b/contracts/token/ERC1155/enumerable/ERC1155EnumerableInternal.sol
@@ -19,7 +19,10 @@ abstract contract ERC1155EnumerableInternal is ERC1155BaseInternal {
      * @return token supply
      */
     function _totalSupply(uint256 id) internal view virtual returns (uint256) {
-        return ERC1155EnumerableStorage.layout().totalSupply[id];
+        return
+            ERC1155EnumerableStorage
+                .layout(ERC1155EnumerableStorage.DEFAULT_STORAGE_SLOT)
+                .totalSupply[id];
     }
 
     /**
@@ -28,7 +31,11 @@ abstract contract ERC1155EnumerableInternal is ERC1155BaseInternal {
      * @return quantity of holders
      */
     function _totalHolders(uint256 id) internal view virtual returns (uint256) {
-        return ERC1155EnumerableStorage.layout().accountsByToken[id].length();
+        return
+            ERC1155EnumerableStorage
+                .layout(ERC1155EnumerableStorage.DEFAULT_STORAGE_SLOT)
+                .accountsByToken[id]
+                .length();
     }
 
     /**
@@ -40,7 +47,7 @@ abstract contract ERC1155EnumerableInternal is ERC1155BaseInternal {
         uint256 id
     ) internal view virtual returns (address[] memory) {
         EnumerableSet.AddressSet storage accounts = ERC1155EnumerableStorage
-            .layout()
+            .layout(ERC1155EnumerableStorage.DEFAULT_STORAGE_SLOT)
             .accountsByToken[id];
 
         address[] memory addresses = new address[](accounts.length());
@@ -63,7 +70,7 @@ abstract contract ERC1155EnumerableInternal is ERC1155BaseInternal {
         address account
     ) internal view virtual returns (uint256[] memory) {
         EnumerableSet.UintSet storage tokens = ERC1155EnumerableStorage
-            .layout()
+            .layout(ERC1155EnumerableStorage.DEFAULT_STORAGE_SLOT)
             .tokensByAccount[account];
 
         uint256[] memory ids = new uint256[](tokens.length());
@@ -93,7 +100,7 @@ abstract contract ERC1155EnumerableInternal is ERC1155BaseInternal {
 
         if (from != to) {
             ERC1155EnumerableStorage.Layout storage l = ERC1155EnumerableStorage
-                .layout();
+                .layout(ERC1155EnumerableStorage.DEFAULT_STORAGE_SLOT);
             mapping(uint256 => EnumerableSet.AddressSet)
                 storage tokenAccounts = l.accountsByToken;
             EnumerableSet.UintSet storage fromTokens = l.tokensByAccount[from];
diff --git a/contracts/token/ERC1155/enumerable/ERC1155EnumerableStorage.sol b/contracts/token/ERC1155/enumerable/ERC1155EnumerableStorage.sol
index 957c9d74..5b6a96cd 100644
--- a/contracts/token/ERC1155/enumerable/ERC1155EnumerableStorage.sol
+++ b/contracts/token/ERC1155/enumerable/ERC1155EnumerableStorage.sol
@@ -11,11 +11,22 @@ library ERC1155EnumerableStorage {
         mapping(address => EnumerableSet.UintSet) tokensByAccount;
     }
 
-    bytes32 internal constant STORAGE_SLOT =
-        keccak256('solidstate.contracts.storage.ERC1155Enumerable');
+    bytes32 internal constant DEFAULT_STORAGE_SLOT =
+        keccak256(
+            abi.encode(
+                uint256(
+                    keccak256(
+                        bytes('solidstate.contracts.storage.ERC1155Enumerable')
+                    )
+                ) - 1
+            )
+        ) & ~bytes32(uint256(0xff));
 
     function layout() internal pure returns (Layout storage l) {
-        bytes32 slot = STORAGE_SLOT;
+        l = layout(DEFAULT_STORAGE_SLOT);
+    }
+
+    function layout(bytes32 slot) internal pure returns (Layout storage l) {
         assembly {
             l.slot := slot
         }
diff --git a/contracts/token/ERC1155/metadata/ERC1155Metadata.sol b/contracts/token/ERC1155/metadata/ERC1155Metadata.sol
index b267b8d7..6a251280 100644
--- a/contracts/token/ERC1155/metadata/ERC1155Metadata.sol
+++ b/contracts/token/ERC1155/metadata/ERC1155Metadata.sol
@@ -17,8 +17,9 @@ abstract contract ERC1155Metadata is IERC1155Metadata, ERC1155MetadataInternal {
      * @notice inheritdoc IERC1155Metadata
      */
     function uri(uint256 tokenId) public view virtual returns (string memory) {
-        ERC1155MetadataStorage.Layout storage l = ERC1155MetadataStorage
-            .layout();
+        ERC1155MetadataStorage.Layout storage l = ERC1155MetadataStorage.layout(
+            ERC1155MetadataStorage.DEFAULT_STORAGE_SLOT
+        );
 
         string memory tokenIdURI = l.tokenURIs[tokenId];
         string memory baseURI = l.baseURI;
diff --git a/contracts/token/ERC1155/metadata/ERC1155MetadataInternal.sol b/contracts/token/ERC1155/metadata/ERC1155MetadataInternal.sol
index e34aad11..cccdc896 100644
--- a/contracts/token/ERC1155/metadata/ERC1155MetadataInternal.sol
+++ b/contracts/token/ERC1155/metadata/ERC1155MetadataInternal.sol
@@ -15,7 +15,9 @@ abstract contract ERC1155MetadataInternal is IERC1155MetadataInternal {
      * @param baseURI base URI
      */
     function _setBaseURI(string memory baseURI) internal {
-        ERC1155MetadataStorage.layout().baseURI = baseURI;
+        ERC1155MetadataStorage
+            .layout(ERC1155MetadataStorage.DEFAULT_STORAGE_SLOT)
+            .baseURI = baseURI;
     }
 
     /**
@@ -24,7 +26,9 @@ abstract contract ERC1155MetadataInternal is IERC1155MetadataInternal {
      * @param tokenURI per-token URI
      */
     function _setTokenURI(uint256 tokenId, string memory tokenURI) internal {
-        ERC1155MetadataStorage.layout().tokenURIs[tokenId] = tokenURI;
+        ERC1155MetadataStorage
+            .layout(ERC1155MetadataStorage.DEFAULT_STORAGE_SLOT)
+            .tokenURIs[tokenId] = tokenURI;
         emit URI(tokenURI, tokenId);
     }
 }
diff --git a/contracts/token/ERC1155/metadata/ERC1155MetadataMock.sol b/contracts/token/ERC1155/metadata/ERC1155MetadataMock.sol
index 03c91522..c82712ed 100644
--- a/contracts/token/ERC1155/metadata/ERC1155MetadataMock.sol
+++ b/contracts/token/ERC1155/metadata/ERC1155MetadataMock.sol
@@ -7,6 +7,8 @@ import { ERC165Base } from '../../../introspection/ERC165/base/ERC165Base.sol';
 
 contract ERC1155MetadataMock is ERC1155Metadata, ERC165Base {
     constructor(string memory baseURI) {
-        ERC1155MetadataStorage.layout().baseURI = baseURI;
+        ERC1155MetadataStorage
+            .layout(ERC1155MetadataStorage.DEFAULT_STORAGE_SLOT)
+            .baseURI = baseURI;
     }
 }
diff --git a/contracts/token/ERC1155/metadata/ERC1155MetadataStorage.sol b/contracts/token/ERC1155/metadata/ERC1155MetadataStorage.sol
index fd453dc9..ea0c0d19 100644
--- a/contracts/token/ERC1155/metadata/ERC1155MetadataStorage.sol
+++ b/contracts/token/ERC1155/metadata/ERC1155MetadataStorage.sol
@@ -6,8 +6,16 @@ pragma solidity ^0.8.20;
  * @title ERC1155 metadata extensions
  */
 library ERC1155MetadataStorage {
-    bytes32 internal constant STORAGE_SLOT =
-        keccak256('solidstate.contracts.storage.ERC1155Metadata');
+    bytes32 internal constant DEFAULT_STORAGE_SLOT =
+        keccak256(
+            abi.encode(
+                uint256(
+                    keccak256(
+                        bytes('solidstate.contracts.storage.ERC1155Metadata')
+                    )
+                ) - 1
+            )
+        ) & ~bytes32(uint256(0xff));
 
     struct Layout {
         string baseURI;
@@ -15,7 +23,10 @@ library ERC1155MetadataStorage {
     }
 
     function layout() internal pure returns (Layout storage l) {
-        bytes32 slot = STORAGE_SLOT;
+        l = layout(DEFAULT_STORAGE_SLOT);
+    }
+
+    function layout(bytes32 slot) internal pure returns (Layout storage l) {
         assembly {
             l.slot := slot
         }
diff --git a/contracts/token/ERC1404/base/ERC1404BaseInternal.sol b/contracts/token/ERC1404/base/ERC1404BaseInternal.sol
index 6c6d516c..740f93a8 100644
--- a/contracts/token/ERC1404/base/ERC1404BaseInternal.sol
+++ b/contracts/token/ERC1404/base/ERC1404BaseInternal.sol
@@ -22,7 +22,7 @@ abstract contract ERC1404BaseInternal is
             revert ERC1404Base__ArrayLengthMismatch();
 
         mapping(uint8 => string) storage restrictions = ERC1404BaseStorage
-            .layout()
+            .layout(ERC1404BaseStorage.DEFAULT_STORAGE_SLOT)
             .restrictions;
 
         unchecked {
@@ -41,7 +41,10 @@ abstract contract ERC1404BaseInternal is
     function _messageForTransferRestriction(
         uint8 restrictionCode
     ) internal view virtual returns (string memory) {
-        return ERC1404BaseStorage.layout().restrictions[restrictionCode];
+        return
+            ERC1404BaseStorage
+                .layout(ERC1404BaseStorage.DEFAULT_STORAGE_SLOT)
+                .restrictions[restrictionCode];
     }
 
     /**
diff --git a/contracts/token/ERC1404/base/ERC1404BaseStorage.sol b/contracts/token/ERC1404/base/ERC1404BaseStorage.sol
index 7f7c8f4b..ced5d93d 100644
--- a/contracts/token/ERC1404/base/ERC1404BaseStorage.sol
+++ b/contracts/token/ERC1404/base/ERC1404BaseStorage.sol
@@ -7,11 +7,20 @@ library ERC1404BaseStorage {
         mapping(uint8 => string) restrictions;
     }
 
-    bytes32 internal constant STORAGE_SLOT =
-        keccak256('solidstate.contracts.storage.ERC1404Base');
+    bytes32 internal constant DEFAULT_STORAGE_SLOT =
+        keccak256(
+            abi.encode(
+                uint256(
+                    keccak256(bytes('solidstate.contracts.storage.ERC1404Base'))
+                ) - 1
+            )
+        ) & ~bytes32(uint256(0xff));
 
     function layout() internal pure returns (Layout storage l) {
-        bytes32 slot = STORAGE_SLOT;
+        l = layout(DEFAULT_STORAGE_SLOT);
+    }
+
+    function layout(bytes32 slot) internal pure returns (Layout storage l) {
         assembly {
             l.slot := slot
         }
diff --git a/contracts/token/ERC20/base/ERC20BaseInternal.sol b/contracts/token/ERC20/base/ERC20BaseInternal.sol
index 6de697ae..3f09dd0f 100644
--- a/contracts/token/ERC20/base/ERC20BaseInternal.sol
+++ b/contracts/token/ERC20/base/ERC20BaseInternal.sol
@@ -14,7 +14,10 @@ abstract contract ERC20BaseInternal is IERC20BaseInternal {
      * @return token supply
      */
     function _totalSupply() internal view virtual returns (uint256) {
-        return ERC20BaseStorage.layout().totalSupply;
+        return
+            ERC20BaseStorage
+                .layout(ERC20BaseStorage.DEFAULT_STORAGE_SLOT)
+                .totalSupply;
     }
 
     /**
@@ -25,7 +28,10 @@ abstract contract ERC20BaseInternal is IERC20BaseInternal {
     function _balanceOf(
         address account
     ) internal view virtual returns (uint256) {
-        return ERC20BaseStorage.layout().balances[account];
+        return
+            ERC20BaseStorage
+                .layout(ERC20BaseStorage.DEFAULT_STORAGE_SLOT)
+                .balances[account];
     }
 
     /**
@@ -38,7 +44,10 @@ abstract contract ERC20BaseInternal is IERC20BaseInternal {
         address holder,
         address spender
     ) internal view virtual returns (uint256) {
-        return ERC20BaseStorage.layout().allowances[holder][spender];
+        return
+            ERC20BaseStorage
+                .layout(ERC20BaseStorage.DEFAULT_STORAGE_SLOT)
+                .allowances[holder][spender];
     }
 
     /**
@@ -56,7 +65,9 @@ abstract contract ERC20BaseInternal is IERC20BaseInternal {
         if (holder == address(0)) revert ERC20Base__ApproveFromZeroAddress();
         if (spender == address(0)) revert ERC20Base__ApproveToZeroAddress();
 
-        ERC20BaseStorage.layout().allowances[holder][spender] = amount;
+        ERC20BaseStorage
+            .layout(ERC20BaseStorage.DEFAULT_STORAGE_SLOT)
+            .allowances[holder][spender] = amount;
 
         emit Approval(holder, spender, amount);
 
@@ -93,7 +104,9 @@ abstract contract ERC20BaseInternal is IERC20BaseInternal {
 
         _beforeTokenTransfer(address(0), account, amount);
 
-        ERC20BaseStorage.Layout storage l = ERC20BaseStorage.layout();
+        ERC20BaseStorage.Layout storage l = ERC20BaseStorage.layout(
+            ERC20BaseStorage.DEFAULT_STORAGE_SLOT
+        );
         l.totalSupply += amount;
         l.balances[account] += amount;
 
@@ -110,7 +123,9 @@ abstract contract ERC20BaseInternal is IERC20BaseInternal {
 
         _beforeTokenTransfer(account, address(0), amount);
 
-        ERC20BaseStorage.Layout storage l = ERC20BaseStorage.layout();
+        ERC20BaseStorage.Layout storage l = ERC20BaseStorage.layout(
+            ERC20BaseStorage.DEFAULT_STORAGE_SLOT
+        );
         uint256 balance = l.balances[account];
         if (amount > balance) revert ERC20Base__BurnExceedsBalance();
         unchecked {
@@ -138,7 +153,9 @@ abstract contract ERC20BaseInternal is IERC20BaseInternal {
 
         _beforeTokenTransfer(holder, recipient, amount);
 
-        ERC20BaseStorage.Layout storage l = ERC20BaseStorage.layout();
+        ERC20BaseStorage.Layout storage l = ERC20BaseStorage.layout(
+            ERC20BaseStorage.DEFAULT_STORAGE_SLOT
+        );
         uint256 holderBalance = l.balances[holder];
         if (amount > holderBalance) revert ERC20Base__TransferExceedsBalance();
         unchecked {
diff --git a/contracts/token/ERC20/base/ERC20BaseStorage.sol b/contracts/token/ERC20/base/ERC20BaseStorage.sol
index 89b7e8d4..ded3d6d0 100644
--- a/contracts/token/ERC20/base/ERC20BaseStorage.sol
+++ b/contracts/token/ERC20/base/ERC20BaseStorage.sol
@@ -9,11 +9,20 @@ library ERC20BaseStorage {
         uint256 totalSupply;
     }
 
-    bytes32 internal constant STORAGE_SLOT =
-        keccak256('solidstate.contracts.storage.ERC20Base');
+    bytes32 internal constant DEFAULT_STORAGE_SLOT =
+        keccak256(
+            abi.encode(
+                uint256(
+                    keccak256(bytes('solidstate.contracts.storage.ERC20Base'))
+                ) - 1
+            )
+        ) & ~bytes32(uint256(0xff));
 
     function layout() internal pure returns (Layout storage l) {
-        bytes32 slot = STORAGE_SLOT;
+        l = layout(DEFAULT_STORAGE_SLOT);
+    }
+
+    function layout(bytes32 slot) internal pure returns (Layout storage l) {
         assembly {
             l.slot := slot
         }
diff --git a/contracts/token/ERC20/implicit_approval/ERC20ImplicitApprovalInternal.sol b/contracts/token/ERC20/implicit_approval/ERC20ImplicitApprovalInternal.sol
index cf8ba444..8f61276f 100644
--- a/contracts/token/ERC20/implicit_approval/ERC20ImplicitApprovalInternal.sol
+++ b/contracts/token/ERC20/implicit_approval/ERC20ImplicitApprovalInternal.sol
@@ -49,6 +49,9 @@ abstract contract ERC20ImplicitApprovalInternal is ERC20BaseInternal {
     function _isImplicitlyApproved(
         address account
     ) internal view virtual returns (bool) {
-        return ERC20ImplicitApprovalStorage.layout().implicitApprovals[account];
+        return
+            ERC20ImplicitApprovalStorage
+                .layout(ERC20ImplicitApprovalStorage.DEFAULT_STORAGE_SLOT)
+                .implicitApprovals[account];
     }
 }
diff --git a/contracts/token/ERC20/implicit_approval/ERC20ImplicitApprovalMock.sol b/contracts/token/ERC20/implicit_approval/ERC20ImplicitApprovalMock.sol
index 68a464f1..d0174237 100644
--- a/contracts/token/ERC20/implicit_approval/ERC20ImplicitApprovalMock.sol
+++ b/contracts/token/ERC20/implicit_approval/ERC20ImplicitApprovalMock.sol
@@ -8,7 +8,9 @@ import { ERC20ImplicitApprovalStorage } from './ERC20ImplicitApprovalStorage.sol
 contract ERC20ImplicitApprovalMock is ERC20ImplicitApproval {
     constructor(address[] memory approvedAccounts) {
         ERC20ImplicitApprovalStorage.Layout
-            storage l = ERC20ImplicitApprovalStorage.layout();
+            storage l = ERC20ImplicitApprovalStorage.layout(
+                ERC20ImplicitApprovalStorage.DEFAULT_STORAGE_SLOT
+            );
 
         for (uint256 i; i < approvedAccounts.length; i++) {
             l.implicitApprovals[approvedAccounts[i]] = true;
diff --git a/contracts/token/ERC20/implicit_approval/ERC20ImplicitApprovalStorage.sol b/contracts/token/ERC20/implicit_approval/ERC20ImplicitApprovalStorage.sol
index 82ac22e9..8e2f9f7b 100644
--- a/contracts/token/ERC20/implicit_approval/ERC20ImplicitApprovalStorage.sol
+++ b/contracts/token/ERC20/implicit_approval/ERC20ImplicitApprovalStorage.sol
@@ -7,11 +7,24 @@ library ERC20ImplicitApprovalStorage {
         mapping(address => bool) implicitApprovals;
     }
 
-    bytes32 internal constant STORAGE_SLOT =
-        keccak256('solidstate.contracts.storage.ERC20ImplicitApproval');
+    bytes32 internal constant DEFAULT_STORAGE_SLOT =
+        keccak256(
+            abi.encode(
+                uint256(
+                    keccak256(
+                        bytes(
+                            'solidstate.contracts.storage.ERC20ImplicitApproval'
+                        )
+                    )
+                ) - 1
+            )
+        ) & ~bytes32(uint256(0xff));
 
     function layout() internal pure returns (Layout storage l) {
-        bytes32 slot = STORAGE_SLOT;
+        l = layout(DEFAULT_STORAGE_SLOT);
+    }
+
+    function layout(bytes32 slot) internal pure returns (Layout storage l) {
         assembly {
             l.slot := slot
         }
diff --git a/contracts/token/ERC20/metadata/ERC20MetadataInternal.sol b/contracts/token/ERC20/metadata/ERC20MetadataInternal.sol
index a749fb08..cff232ce 100644
--- a/contracts/token/ERC20/metadata/ERC20MetadataInternal.sol
+++ b/contracts/token/ERC20/metadata/ERC20MetadataInternal.sol
@@ -14,7 +14,10 @@ abstract contract ERC20MetadataInternal is IERC20MetadataInternal {
      * @return token name
      */
     function _name() internal view virtual returns (string memory) {
-        return ERC20MetadataStorage.layout().name;
+        return
+            ERC20MetadataStorage
+                .layout(ERC20MetadataStorage.DEFAULT_STORAGE_SLOT)
+                .name;
     }
 
     /**
@@ -22,7 +25,10 @@ abstract contract ERC20MetadataInternal is IERC20MetadataInternal {
      * @return token symbol
      */
     function _symbol() internal view virtual returns (string memory) {
-        return ERC20MetadataStorage.layout().symbol;
+        return
+            ERC20MetadataStorage
+                .layout(ERC20MetadataStorage.DEFAULT_STORAGE_SLOT)
+                .symbol;
     }
 
     /**
@@ -30,18 +36,27 @@ abstract contract ERC20MetadataInternal is IERC20MetadataInternal {
      * @return token decimals
      */
     function _decimals() internal view virtual returns (uint8) {
-        return ERC20MetadataStorage.layout().decimals;
+        return
+            ERC20MetadataStorage
+                .layout(ERC20MetadataStorage.DEFAULT_STORAGE_SLOT)
+                .decimals;
     }
 
     function _setName(string memory name) internal virtual {
-        ERC20MetadataStorage.layout().name = name;
+        ERC20MetadataStorage
+            .layout(ERC20MetadataStorage.DEFAULT_STORAGE_SLOT)
+            .name = name;
     }
 
     function _setSymbol(string memory symbol) internal virtual {
-        ERC20MetadataStorage.layout().symbol = symbol;
+        ERC20MetadataStorage
+            .layout(ERC20MetadataStorage.DEFAULT_STORAGE_SLOT)
+            .symbol = symbol;
     }
 
     function _setDecimals(uint8 decimals) internal virtual {
-        ERC20MetadataStorage.layout().decimals = decimals;
+        ERC20MetadataStorage
+            .layout(ERC20MetadataStorage.DEFAULT_STORAGE_SLOT)
+            .decimals = decimals;
     }
 }
diff --git a/contracts/token/ERC20/metadata/ERC20MetadataStorage.sol b/contracts/token/ERC20/metadata/ERC20MetadataStorage.sol
index ba1ce09f..83d9e2e0 100644
--- a/contracts/token/ERC20/metadata/ERC20MetadataStorage.sol
+++ b/contracts/token/ERC20/metadata/ERC20MetadataStorage.sol
@@ -9,11 +9,22 @@ library ERC20MetadataStorage {
         uint8 decimals;
     }
 
-    bytes32 internal constant STORAGE_SLOT =
-        keccak256('solidstate.contracts.storage.ERC20Metadata');
+    bytes32 internal constant DEFAULT_STORAGE_SLOT =
+        keccak256(
+            abi.encode(
+                uint256(
+                    keccak256(
+                        bytes('solidstate.contracts.storage.ERC20Metadata')
+                    )
+                ) - 1
+            )
+        ) & ~bytes32(uint256(0xff));
 
     function layout() internal pure returns (Layout storage l) {
-        bytes32 slot = STORAGE_SLOT;
+        l = layout(DEFAULT_STORAGE_SLOT);
+    }
+
+    function layout(bytes32 slot) internal pure returns (Layout storage l) {
         assembly {
             l.slot := slot
         }
diff --git a/contracts/token/ERC20/permit/ERC20PermitInternal.sol b/contracts/token/ERC20/permit/ERC20PermitInternal.sol
index f7ac96d5..3ca0bebb 100644
--- a/contracts/token/ERC20/permit/ERC20PermitInternal.sol
+++ b/contracts/token/ERC20/permit/ERC20PermitInternal.sol
@@ -34,9 +34,9 @@ abstract contract ERC20PermitInternal is
         view
         returns (bytes32 domainSeparator)
     {
-        domainSeparator = ERC20PermitStorage.layout().domainSeparators[
-            block.chainid
-        ];
+        domainSeparator = ERC20PermitStorage
+            .layout(ERC20PermitStorage.DEFAULT_STORAGE_SLOT)
+            .domainSeparators[block.chainid];
 
         if (domainSeparator == 0x00) {
             domainSeparator = EIP712.calculateDomainSeparator(
@@ -51,7 +51,10 @@ abstract contract ERC20PermitInternal is
      * @return current nonce
      */
     function _nonces(address owner) internal view returns (uint256) {
-        return ERC20PermitStorage.layout().nonces[owner];
+        return
+            ERC20PermitStorage
+                .layout(ERC20PermitStorage.DEFAULT_STORAGE_SLOT)
+                .nonces[owner];
     }
 
     /**
@@ -83,7 +86,9 @@ abstract contract ERC20PermitInternal is
     ) internal virtual {
         if (deadline < block.timestamp) revert ERC20Permit__ExpiredDeadline();
 
-        ERC20PermitStorage.Layout storage l = ERC20PermitStorage.layout();
+        ERC20PermitStorage.Layout storage l = ERC20PermitStorage.layout(
+            ERC20PermitStorage.DEFAULT_STORAGE_SLOT
+        );
 
         // execute EIP-712 hashStruct procedure using assembly, equavalent to:
         //
@@ -173,6 +178,8 @@ abstract contract ERC20PermitInternal is
     function _setName(string memory name) internal virtual override {
         // TODO: cache invalidation can fail if chainid is reverted to a previous value
         super._setName(name);
-        delete ERC20PermitStorage.layout().domainSeparators[block.chainid];
+        delete ERC20PermitStorage
+            .layout(ERC20PermitStorage.DEFAULT_STORAGE_SLOT)
+            .domainSeparators[block.chainid];
     }
 }
diff --git a/contracts/token/ERC20/permit/ERC20PermitMock.sol b/contracts/token/ERC20/permit/ERC20PermitMock.sol
index 66dc0b97..67bf57e9 100644
--- a/contracts/token/ERC20/permit/ERC20PermitMock.sol
+++ b/contracts/token/ERC20/permit/ERC20PermitMock.sol
@@ -8,7 +8,9 @@ import { ERC20Permit } from './ERC20Permit.sol';
 
 contract ERC20PermitMock is ERC20Permit, ERC20Base {
     constructor(string memory tokenName) {
-        ERC20MetadataStorage.layout().name = tokenName;
+        ERC20MetadataStorage
+            .layout(ERC20MetadataStorage.DEFAULT_STORAGE_SLOT)
+            .name = tokenName;
     }
 
     /**
diff --git a/contracts/token/ERC20/permit/ERC20PermitStorage.sol b/contracts/token/ERC20/permit/ERC20PermitStorage.sol
index 383d3c3e..ef415b16 100644
--- a/contracts/token/ERC20/permit/ERC20PermitStorage.sol
+++ b/contracts/token/ERC20/permit/ERC20PermitStorage.sol
@@ -11,11 +11,20 @@ library ERC20PermitStorage {
         mapping(uint256 => bytes32) domainSeparators;
     }
 
-    bytes32 internal constant STORAGE_SLOT =
-        keccak256('solidstate.contracts.storage.ERC20Permit');
+    bytes32 internal constant DEFAULT_STORAGE_SLOT =
+        keccak256(
+            abi.encode(
+                uint256(
+                    keccak256(bytes('solidstate.contracts.storage.ERC20Permit'))
+                ) - 1
+            )
+        ) & ~bytes32(uint256(0xff));
 
     function layout() internal pure returns (Layout storage l) {
-        bytes32 slot = STORAGE_SLOT;
+        l = layout(DEFAULT_STORAGE_SLOT);
+    }
+
+    function layout(bytes32 slot) internal pure returns (Layout storage l) {
         assembly {
             l.slot := slot
         }
diff --git a/contracts/token/ERC20/snapshot/ERC20Snapshot.sol b/contracts/token/ERC20/snapshot/ERC20Snapshot.sol
index 9e9d2b1e..6809ee68 100644
--- a/contracts/token/ERC20/snapshot/ERC20Snapshot.sol
+++ b/contracts/token/ERC20/snapshot/ERC20Snapshot.sol
@@ -24,7 +24,9 @@ abstract contract ERC20Snapshot is ERC20SnapshotInternal {
     ) public view returns (uint256) {
         (bool snapshotted, uint256 value) = _valueAt(
             snapshotId,
-            ERC20SnapshotStorage.layout().accountBalanceSnapshots[account]
+            ERC20SnapshotStorage
+                .layout(ERC20SnapshotStorage.DEFAULT_STORAGE_SLOT)
+                .accountBalanceSnapshots[account]
         );
         return snapshotted ? value : _balanceOf(account);
     }
@@ -37,7 +39,9 @@ abstract contract ERC20Snapshot is ERC20SnapshotInternal {
     function totalSupplyAt(uint256 snapshotId) public view returns (uint256) {
         (bool snapshotted, uint256 value) = _valueAt(
             snapshotId,
-            ERC20SnapshotStorage.layout().totalSupplySnapshots
+            ERC20SnapshotStorage
+                .layout(ERC20SnapshotStorage.DEFAULT_STORAGE_SLOT)
+                .totalSupplySnapshots
         );
         return snapshotted ? value : _totalSupply();
     }
@@ -47,7 +51,9 @@ abstract contract ERC20Snapshot is ERC20SnapshotInternal {
         ERC20SnapshotStorage.Snapshots storage snapshots
     ) private view returns (bool, uint256) {
         if (snapshotId == 0) revert ERC20Snapshot__SnapshotIdIsZero();
-        ERC20SnapshotStorage.Layout storage l = ERC20SnapshotStorage.layout();
+        ERC20SnapshotStorage.Layout storage l = ERC20SnapshotStorage.layout(
+            ERC20SnapshotStorage.DEFAULT_STORAGE_SLOT
+        );
 
         if (snapshotId > l.snapshotId)
             revert ERC20Snapshot__SnapshotIdDoesNotExists();
diff --git a/contracts/token/ERC20/snapshot/ERC20SnapshotInternal.sol b/contracts/token/ERC20/snapshot/ERC20SnapshotInternal.sol
index f4bdb93c..0cf35700 100644
--- a/contracts/token/ERC20/snapshot/ERC20SnapshotInternal.sol
+++ b/contracts/token/ERC20/snapshot/ERC20SnapshotInternal.sol
@@ -12,7 +12,9 @@ abstract contract ERC20SnapshotInternal is ERC20BaseInternal {
     event Snapshot(uint256 id);
 
     function _snapshot() internal virtual returns (uint256) {
-        ERC20SnapshotStorage.Layout storage l = ERC20SnapshotStorage.layout();
+        ERC20SnapshotStorage.Layout storage l = ERC20SnapshotStorage.layout(
+            ERC20SnapshotStorage.DEFAULT_STORAGE_SLOT
+        );
 
         l.snapshotId++;
 
@@ -23,14 +25,18 @@ abstract contract ERC20SnapshotInternal is ERC20BaseInternal {
 
     function _updateAccountSnapshot(address account) private {
         _updateSnapshot(
-            ERC20SnapshotStorage.layout().accountBalanceSnapshots[account],
+            ERC20SnapshotStorage
+                .layout(ERC20SnapshotStorage.DEFAULT_STORAGE_SLOT)
+                .accountBalanceSnapshots[account],
             _balanceOf(account)
         );
     }
 
     function _updateTotalSupplySnapshot() private {
         _updateSnapshot(
-            ERC20SnapshotStorage.layout().totalSupplySnapshots,
+            ERC20SnapshotStorage
+                .layout(ERC20SnapshotStorage.DEFAULT_STORAGE_SLOT)
+                .totalSupplySnapshots,
             _totalSupply()
         );
     }
@@ -39,7 +45,9 @@ abstract contract ERC20SnapshotInternal is ERC20BaseInternal {
         ERC20SnapshotStorage.Snapshots storage snapshots,
         uint256 value
     ) private {
-        uint256 current = ERC20SnapshotStorage.layout().snapshotId;
+        uint256 current = ERC20SnapshotStorage
+            .layout(ERC20SnapshotStorage.DEFAULT_STORAGE_SLOT)
+            .snapshotId;
 
         if (_lastSnapshotId(snapshots.ids) < current) {
             snapshots.ids.push(current);
diff --git a/contracts/token/ERC20/snapshot/ERC20SnapshotStorage.sol b/contracts/token/ERC20/snapshot/ERC20SnapshotStorage.sol
index 9c766d0b..267e5eb7 100644
--- a/contracts/token/ERC20/snapshot/ERC20SnapshotStorage.sol
+++ b/contracts/token/ERC20/snapshot/ERC20SnapshotStorage.sol
@@ -14,11 +14,22 @@ library ERC20SnapshotStorage {
         uint256 snapshotId;
     }
 
-    bytes32 internal constant STORAGE_SLOT =
-        keccak256('solidstate.contracts.storage.ERC20Snapshot');
+    bytes32 internal constant DEFAULT_STORAGE_SLOT =
+        keccak256(
+            abi.encode(
+                uint256(
+                    keccak256(
+                        bytes('solidstate.contracts.storage.ERC20Snapshot')
+                    )
+                ) - 1
+            )
+        ) & ~bytes32(uint256(0xff));
 
     function layout() internal pure returns (Layout storage l) {
-        bytes32 slot = STORAGE_SLOT;
+        l = layout(DEFAULT_STORAGE_SLOT);
+    }
+
+    function layout(bytes32 slot) internal pure returns (Layout storage l) {
         assembly {
             l.slot := slot
         }
diff --git a/contracts/token/ERC4626/SolidStateERC4626Mock.sol b/contracts/token/ERC4626/SolidStateERC4626Mock.sol
index 677a8f5e..a587ec8a 100644
--- a/contracts/token/ERC4626/SolidStateERC4626Mock.sol
+++ b/contracts/token/ERC4626/SolidStateERC4626Mock.sol
@@ -24,9 +24,13 @@ contract SolidStateERC4626Mock is SolidStateERC4626 {
         string memory symbol,
         uint8 decimals
     ) {
-        ERC4626BaseStorage.layout().asset = asset;
+        ERC4626BaseStorage
+            .layout(ERC4626BaseStorage.DEFAULT_STORAGE_SLOT)
+            .asset = asset;
 
-        ERC20MetadataStorage.Layout storage l = ERC20MetadataStorage.layout();
+        ERC20MetadataStorage.Layout storage l = ERC20MetadataStorage.layout(
+            ERC20MetadataStorage.DEFAULT_STORAGE_SLOT
+        );
         l.name = name;
         l.symbol = symbol;
         l.decimals = decimals;
diff --git a/contracts/token/ERC4626/base/ERC4626BaseInternal.sol b/contracts/token/ERC4626/base/ERC4626BaseInternal.sol
index 2b7e729c..8b809d82 100644
--- a/contracts/token/ERC4626/base/ERC4626BaseInternal.sol
+++ b/contracts/token/ERC4626/base/ERC4626BaseInternal.sol
@@ -24,7 +24,10 @@ abstract contract ERC4626BaseInternal is
      * @return base token address
      */
     function _asset() internal view virtual returns (address) {
-        return ERC4626BaseStorage.layout().asset;
+        return
+            ERC4626BaseStorage
+                .layout(ERC4626BaseStorage.DEFAULT_STORAGE_SLOT)
+                .asset;
     }
 
     /**
diff --git a/contracts/token/ERC4626/base/ERC4626BaseMock.sol b/contracts/token/ERC4626/base/ERC4626BaseMock.sol
index 5132eab9..583e21a7 100644
--- a/contracts/token/ERC4626/base/ERC4626BaseMock.sol
+++ b/contracts/token/ERC4626/base/ERC4626BaseMock.sol
@@ -24,9 +24,13 @@ contract ERC4626BaseMock is ERC4626Base {
         string memory symbol,
         uint8 decimals
     ) {
-        ERC4626BaseStorage.layout().asset = asset;
+        ERC4626BaseStorage
+            .layout(ERC4626BaseStorage.DEFAULT_STORAGE_SLOT)
+            .asset = asset;
 
-        ERC20MetadataStorage.Layout storage l = ERC20MetadataStorage.layout();
+        ERC20MetadataStorage.Layout storage l = ERC20MetadataStorage.layout(
+            ERC20MetadataStorage.DEFAULT_STORAGE_SLOT
+        );
         l.name = name;
         l.symbol = symbol;
         l.decimals = decimals;
diff --git a/contracts/token/ERC4626/base/ERC4626BaseStorage.sol b/contracts/token/ERC4626/base/ERC4626BaseStorage.sol
index a236dfd2..b2c101f1 100644
--- a/contracts/token/ERC4626/base/ERC4626BaseStorage.sol
+++ b/contracts/token/ERC4626/base/ERC4626BaseStorage.sol
@@ -7,11 +7,20 @@ library ERC4626BaseStorage {
         address asset;
     }
 
-    bytes32 internal constant STORAGE_SLOT =
-        keccak256('solidstate.contracts.storage.ERC4626Base');
+    bytes32 internal constant DEFAULT_STORAGE_SLOT =
+        keccak256(
+            abi.encode(
+                uint256(
+                    keccak256(bytes('solidstate.contracts.storage.ERC4626Base'))
+                ) - 1
+            )
+        ) & ~bytes32(uint256(0xff));
 
     function layout() internal pure returns (Layout storage l) {
-        bytes32 slot = STORAGE_SLOT;
+        l = layout(DEFAULT_STORAGE_SLOT);
+    }
+
+    function layout(bytes32 slot) internal pure returns (Layout storage l) {
         assembly {
             l.slot := slot
         }
diff --git a/contracts/token/ERC721/SolidStateERC721Mock.sol b/contracts/token/ERC721/SolidStateERC721Mock.sol
index 7a5a3ce1..84533f31 100644
--- a/contracts/token/ERC721/SolidStateERC721Mock.sol
+++ b/contracts/token/ERC721/SolidStateERC721Mock.sol
@@ -13,7 +13,9 @@ contract SolidStateERC721Mock is SolidStateERC721 {
         string memory symbol,
         string memory baseURI
     ) {
-        ERC721MetadataStorage.Layout storage l = ERC721MetadataStorage.layout();
+        ERC721MetadataStorage.Layout storage l = ERC721MetadataStorage.layout(
+            ERC721MetadataStorage.DEFAULT_STORAGE_SLOT
+        );
         l.name = name;
         l.symbol = symbol;
         l.baseURI = baseURI;
diff --git a/contracts/token/ERC721/base/ERC721BaseInternal.sol b/contracts/token/ERC721/base/ERC721BaseInternal.sol
index 5ead5f4e..60cfde1d 100644
--- a/contracts/token/ERC721/base/ERC721BaseInternal.sol
+++ b/contracts/token/ERC721/base/ERC721BaseInternal.sol
@@ -21,17 +21,28 @@ abstract contract ERC721BaseInternal is IERC721BaseInternal {
         address account
     ) internal view virtual returns (uint256) {
         if (account == address(0)) revert ERC721Base__BalanceQueryZeroAddress();
-        return ERC721BaseStorage.layout().holderTokens[account].length();
+        return
+            ERC721BaseStorage
+                .layout(ERC721BaseStorage.DEFAULT_STORAGE_SLOT)
+                .holderTokens[account]
+                .length();
     }
 
     function _ownerOf(uint256 tokenId) internal view virtual returns (address) {
-        address owner = ERC721BaseStorage.layout().tokenOwners.get(tokenId);
+        address owner = ERC721BaseStorage
+            .layout(ERC721BaseStorage.DEFAULT_STORAGE_SLOT)
+            .tokenOwners
+            .get(tokenId);
         if (owner == address(0)) revert ERC721Base__InvalidOwner();
         return owner;
     }
 
     function _exists(uint256 tokenId) internal view virtual returns (bool) {
-        return ERC721BaseStorage.layout().tokenOwners.contains(tokenId);
+        return
+            ERC721BaseStorage
+                .layout(ERC721BaseStorage.DEFAULT_STORAGE_SLOT)
+                .tokenOwners
+                .contains(tokenId);
     }
 
     function _getApproved(
@@ -39,14 +50,20 @@ abstract contract ERC721BaseInternal is IERC721BaseInternal {
     ) internal view virtual returns (address) {
         if (!_exists(tokenId)) revert ERC721Base__NonExistentToken();
 
-        return ERC721BaseStorage.layout().tokenApprovals[tokenId];
+        return
+            ERC721BaseStorage
+                .layout(ERC721BaseStorage.DEFAULT_STORAGE_SLOT)
+                .tokenApprovals[tokenId];
     }
 
     function _isApprovedForAll(
         address account,
         address operator
     ) internal view virtual returns (bool) {
-        return ERC721BaseStorage.layout().operatorApprovals[account][operator];
+        return
+            ERC721BaseStorage
+                .layout(ERC721BaseStorage.DEFAULT_STORAGE_SLOT)
+                .operatorApprovals[account][operator];
     }
 
     function _isApprovedOrOwner(
@@ -68,7 +85,9 @@ abstract contract ERC721BaseInternal is IERC721BaseInternal {
 
         _beforeTokenTransfer(address(0), to, tokenId);
 
-        ERC721BaseStorage.Layout storage l = ERC721BaseStorage.layout();
+        ERC721BaseStorage.Layout storage l = ERC721BaseStorage.layout(
+            ERC721BaseStorage.DEFAULT_STORAGE_SLOT
+        );
 
         l.holderTokens[to].add(tokenId);
         l.tokenOwners.set(tokenId, to);
@@ -95,7 +114,9 @@ abstract contract ERC721BaseInternal is IERC721BaseInternal {
 
         _beforeTokenTransfer(owner, address(0), tokenId);
 
-        ERC721BaseStorage.Layout storage l = ERC721BaseStorage.layout();
+        ERC721BaseStorage.Layout storage l = ERC721BaseStorage.layout(
+            ERC721BaseStorage.DEFAULT_STORAGE_SLOT
+        );
 
         l.holderTokens[owner].remove(tokenId);
         l.tokenOwners.remove(tokenId);
@@ -118,7 +139,9 @@ abstract contract ERC721BaseInternal is IERC721BaseInternal {
 
         _beforeTokenTransfer(from, to, tokenId);
 
-        ERC721BaseStorage.Layout storage l = ERC721BaseStorage.layout();
+        ERC721BaseStorage.Layout storage l = ERC721BaseStorage.layout(
+            ERC721BaseStorage.DEFAULT_STORAGE_SLOT
+        );
 
         l.holderTokens[from].remove(tokenId);
         l.holderTokens[to].add(tokenId);
@@ -180,7 +203,9 @@ abstract contract ERC721BaseInternal is IERC721BaseInternal {
         if (msg.sender != owner && !_isApprovedForAll(owner, msg.sender))
             revert ERC721Base__NotOwnerOrApproved();
 
-        ERC721BaseStorage.layout().tokenApprovals[tokenId] = operator;
+        ERC721BaseStorage
+            .layout(ERC721BaseStorage.DEFAULT_STORAGE_SLOT)
+            .tokenApprovals[tokenId] = operator;
         emit Approval(owner, operator, tokenId);
     }
 
@@ -189,9 +214,9 @@ abstract contract ERC721BaseInternal is IERC721BaseInternal {
         bool status
     ) internal virtual {
         if (operator == msg.sender) revert ERC721Base__SelfApproval();
-        ERC721BaseStorage.layout().operatorApprovals[msg.sender][
-            operator
-        ] = status;
+        ERC721BaseStorage
+            .layout(ERC721BaseStorage.DEFAULT_STORAGE_SLOT)
+            .operatorApprovals[msg.sender][operator] = status;
         emit ApprovalForAll(msg.sender, operator, status);
     }
 
diff --git a/contracts/token/ERC721/base/ERC721BaseStorage.sol b/contracts/token/ERC721/base/ERC721BaseStorage.sol
index 75a07deb..6d560872 100644
--- a/contracts/token/ERC721/base/ERC721BaseStorage.sol
+++ b/contracts/token/ERC721/base/ERC721BaseStorage.sol
@@ -9,8 +9,14 @@ library ERC721BaseStorage {
     using EnumerableSet for EnumerableSet.UintSet;
     using EnumerableMap for EnumerableMap.UintToAddressMap;
 
-    bytes32 internal constant STORAGE_SLOT =
-        keccak256('solidstate.contracts.storage.ERC721Base');
+    bytes32 internal constant DEFAULT_STORAGE_SLOT =
+        keccak256(
+            abi.encode(
+                uint256(
+                    keccak256(bytes('solidstate.contracts.storage.ERC721Base'))
+                ) - 1
+            )
+        ) & ~bytes32(uint256(0xff));
 
     struct Layout {
         EnumerableMap.UintToAddressMap tokenOwners;
@@ -20,7 +26,10 @@ library ERC721BaseStorage {
     }
 
     function layout() internal pure returns (Layout storage l) {
-        bytes32 slot = STORAGE_SLOT;
+        l = layout(DEFAULT_STORAGE_SLOT);
+    }
+
+    function layout(bytes32 slot) internal pure returns (Layout storage l) {
         assembly {
             l.slot := slot
         }
diff --git a/contracts/token/ERC721/enumerable/ERC721EnumerableInternal.sol b/contracts/token/ERC721/enumerable/ERC721EnumerableInternal.sol
index 7d7a7ac6..5179618c 100644
--- a/contracts/token/ERC721/enumerable/ERC721EnumerableInternal.sol
+++ b/contracts/token/ERC721/enumerable/ERC721EnumerableInternal.sol
@@ -14,7 +14,11 @@ abstract contract ERC721EnumerableInternal {
      * @notice TODO
      */
     function _totalSupply() internal view returns (uint256) {
-        return ERC721BaseStorage.layout().tokenOwners.length();
+        return
+            ERC721BaseStorage
+                .layout(ERC721BaseStorage.DEFAULT_STORAGE_SLOT)
+                .tokenOwners
+                .length();
     }
 
     /**
@@ -24,7 +28,11 @@ abstract contract ERC721EnumerableInternal {
         address owner,
         uint256 index
     ) internal view returns (uint256) {
-        return ERC721BaseStorage.layout().holderTokens[owner].at(index);
+        return
+            ERC721BaseStorage
+                .layout(ERC721BaseStorage.DEFAULT_STORAGE_SLOT)
+                .holderTokens[owner]
+                .at(index);
     }
 
     /**
@@ -33,6 +41,9 @@ abstract contract ERC721EnumerableInternal {
     function _tokenByIndex(
         uint256 index
     ) internal view returns (uint256 tokenId) {
-        (tokenId, ) = ERC721BaseStorage.layout().tokenOwners.at(index);
+        (tokenId, ) = ERC721BaseStorage
+            .layout(ERC721BaseStorage.DEFAULT_STORAGE_SLOT)
+            .tokenOwners
+            .at(index);
     }
 }
diff --git a/contracts/token/ERC721/metadata/ERC721MetadataInternal.sol b/contracts/token/ERC721/metadata/ERC721MetadataInternal.sol
index b640dd6c..0ae9c965 100644
--- a/contracts/token/ERC721/metadata/ERC721MetadataInternal.sol
+++ b/contracts/token/ERC721/metadata/ERC721MetadataInternal.sol
@@ -22,7 +22,10 @@ abstract contract ERC721MetadataInternal is
      * @return token name
      */
     function _name() internal view virtual returns (string memory) {
-        return ERC721MetadataStorage.layout().name;
+        return
+            ERC721MetadataStorage
+                .layout(ERC721MetadataStorage.DEFAULT_STORAGE_SLOT)
+                .name;
     }
 
     /**
@@ -30,7 +33,10 @@ abstract contract ERC721MetadataInternal is
      * @return token symbol
      */
     function _symbol() internal view virtual returns (string memory) {
-        return ERC721MetadataStorage.layout().symbol;
+        return
+            ERC721MetadataStorage
+                .layout(ERC721MetadataStorage.DEFAULT_STORAGE_SLOT)
+                .symbol;
     }
 
     /**
@@ -42,7 +48,9 @@ abstract contract ERC721MetadataInternal is
     ) internal view virtual returns (string memory) {
         if (!_exists(tokenId)) revert ERC721Metadata__NonExistentToken();
 
-        ERC721MetadataStorage.Layout storage l = ERC721MetadataStorage.layout();
+        ERC721MetadataStorage.Layout storage l = ERC721MetadataStorage.layout(
+            ERC721MetadataStorage.DEFAULT_STORAGE_SLOT
+        );
 
         string memory tokenIdURI = l.tokenURIs[tokenId];
         string memory baseURI = l.baseURI;
@@ -68,7 +76,9 @@ abstract contract ERC721MetadataInternal is
         super._beforeTokenTransfer(from, to, tokenId);
 
         if (to == address(0)) {
-            delete ERC721MetadataStorage.layout().tokenURIs[tokenId];
+            delete ERC721MetadataStorage
+                .layout(ERC721MetadataStorage.DEFAULT_STORAGE_SLOT)
+                .tokenURIs[tokenId];
         }
     }
 }
diff --git a/contracts/token/ERC721/metadata/ERC721MetadataMock.sol b/contracts/token/ERC721/metadata/ERC721MetadataMock.sol
index 2ed885ee..674f0e4e 100644
--- a/contracts/token/ERC721/metadata/ERC721MetadataMock.sol
+++ b/contracts/token/ERC721/metadata/ERC721MetadataMock.sol
@@ -12,7 +12,9 @@ contract ERC721MetadataMock is ERC721Metadata, ERC165Base {
         string memory symbol,
         string memory baseURI
     ) {
-        ERC721MetadataStorage.Layout storage l = ERC721MetadataStorage.layout();
+        ERC721MetadataStorage.Layout storage l = ERC721MetadataStorage.layout(
+            ERC721MetadataStorage.DEFAULT_STORAGE_SLOT
+        );
         l.name = name;
         l.symbol = symbol;
         l.baseURI = baseURI;
diff --git a/contracts/token/ERC721/metadata/ERC721MetadataStorage.sol b/contracts/token/ERC721/metadata/ERC721MetadataStorage.sol
index 9ee340d2..8f5d685e 100644
--- a/contracts/token/ERC721/metadata/ERC721MetadataStorage.sol
+++ b/contracts/token/ERC721/metadata/ERC721MetadataStorage.sol
@@ -3,8 +3,16 @@
 pragma solidity ^0.8.20;
 
 library ERC721MetadataStorage {
-    bytes32 internal constant STORAGE_SLOT =
-        keccak256('solidstate.contracts.storage.ERC721Metadata');
+    bytes32 internal constant DEFAULT_STORAGE_SLOT =
+        keccak256(
+            abi.encode(
+                uint256(
+                    keccak256(
+                        bytes('solidstate.contracts.storage.ERC721Metadata')
+                    )
+                ) - 1
+            )
+        ) & ~bytes32(uint256(0xff));
 
     struct Layout {
         string name;
@@ -14,7 +22,10 @@ library ERC721MetadataStorage {
     }
 
     function layout() internal pure returns (Layout storage l) {
-        bytes32 slot = STORAGE_SLOT;
+        l = layout(DEFAULT_STORAGE_SLOT);
+    }
+
+    function layout(bytes32 slot) internal pure returns (Layout storage l) {
         assembly {
             l.slot := slot
         }
diff --git a/contracts/token/common/ERC2981/ERC2981Internal.sol b/contracts/token/common/ERC2981/ERC2981Internal.sol
index 38ad7bc1..b7c39bf8 100644
--- a/contracts/token/common/ERC2981/ERC2981Internal.sol
+++ b/contracts/token/common/ERC2981/ERC2981Internal.sol
@@ -37,7 +37,9 @@ abstract contract ERC2981Internal is IERC2981Internal {
     function _getRoyaltyBPS(
         uint256 tokenId
     ) internal view virtual returns (uint16 royaltyBPS) {
-        ERC2981Storage.Layout storage l = ERC2981Storage.layout();
+        ERC2981Storage.Layout storage l = ERC2981Storage.layout(
+            ERC2981Storage.DEFAULT_STORAGE_SLOT
+        );
         royaltyBPS = l.royaltiesBPS[tokenId];
 
         if (royaltyBPS == 0) {
@@ -54,7 +56,9 @@ abstract contract ERC2981Internal is IERC2981Internal {
     function _getRoyaltyReceiver(
         uint256 tokenId
     ) internal view virtual returns (address royaltyReceiver) {
-        ERC2981Storage.Layout storage l = ERC2981Storage.layout();
+        ERC2981Storage.Layout storage l = ERC2981Storage.layout(
+            ERC2981Storage.DEFAULT_STORAGE_SLOT
+        );
         royaltyReceiver = l.royaltyReceivers[tokenId];
 
         if (royaltyReceiver == address(0)) {
diff --git a/contracts/token/common/ERC2981/ERC2981Mock.sol b/contracts/token/common/ERC2981/ERC2981Mock.sol
index 690f6b40..6925c3dc 100644
--- a/contracts/token/common/ERC2981/ERC2981Mock.sol
+++ b/contracts/token/common/ERC2981/ERC2981Mock.sol
@@ -13,7 +13,9 @@ contract ERC2981Mock is ERC2981, ERC165Base {
         uint16[] memory royaltiesBPS,
         address defaultRoyaltyReceiver
     ) {
-        ERC2981Storage.Layout storage l = ERC2981Storage.layout();
+        ERC2981Storage.Layout storage l = ERC2981Storage.layout(
+            ERC2981Storage.DEFAULT_STORAGE_SLOT
+        );
         l.defaultRoyaltyBPS = defaultRoyaltyBPS;
         l.defaultRoyaltyReceiver = defaultRoyaltyReceiver;
 
@@ -26,6 +28,8 @@ contract ERC2981Mock is ERC2981, ERC165Base {
     }
 
     function setRoyalty(uint16 defaultRoyaltyBPS) external {
-        ERC2981Storage.layout().defaultRoyaltyBPS = defaultRoyaltyBPS;
+        ERC2981Storage
+            .layout(ERC2981Storage.DEFAULT_STORAGE_SLOT)
+            .defaultRoyaltyBPS = defaultRoyaltyBPS;
     }
 }
diff --git a/contracts/token/common/ERC2981/ERC2981Storage.sol b/contracts/token/common/ERC2981/ERC2981Storage.sol
index 74b4c65a..9a13fb8a 100644
--- a/contracts/token/common/ERC2981/ERC2981Storage.sol
+++ b/contracts/token/common/ERC2981/ERC2981Storage.sol
@@ -12,11 +12,20 @@ library ERC2981Storage {
         address defaultRoyaltyReceiver;
     }
 
-    bytes32 internal constant STORAGE_SLOT =
-        keccak256('solidstate.contracts.storage.ERC2981');
+    bytes32 internal constant DEFAULT_STORAGE_SLOT =
+        keccak256(
+            abi.encode(
+                uint256(
+                    keccak256(bytes('solidstate.contracts.storage.ERC2981'))
+                ) - 1
+            )
+        ) & ~bytes32(uint256(0xff));
 
     function layout() internal pure returns (Layout storage l) {
-        bytes32 slot = STORAGE_SLOT;
+        l = layout(DEFAULT_STORAGE_SLOT);
+    }
+
+    function layout(bytes32 slot) internal pure returns (Layout storage l) {
         assembly {
             l.slot := slot
         }
diff --git a/spec/signature/base/ERC1271Base.behavior.ts b/spec/signature/ERC1271/base/ERC1271Base.behavior.ts
similarity index 100%
rename from spec/signature/base/ERC1271Base.behavior.ts
rename to spec/signature/ERC1271/base/ERC1271Base.behavior.ts
diff --git a/spec/signature/base/index.ts b/spec/signature/ERC1271/base/index.ts
similarity index 100%
rename from spec/signature/base/index.ts
rename to spec/signature/ERC1271/base/index.ts
diff --git a/spec/signature/ERC1271/index.ts b/spec/signature/ERC1271/index.ts
new file mode 100644
index 00000000..3913577d
--- /dev/null
+++ b/spec/signature/ERC1271/index.ts
@@ -0,0 +1,3 @@
+export * from './base';
+export * from './ownable';
+export * from './stored';
diff --git a/spec/signature/ownable/ERC1271Ownable.behavior.ts b/spec/signature/ERC1271/ownable/ERC1271Ownable.behavior.ts
similarity index 100%
rename from spec/signature/ownable/ERC1271Ownable.behavior.ts
rename to spec/signature/ERC1271/ownable/ERC1271Ownable.behavior.ts
diff --git a/spec/signature/ownable/index.ts b/spec/signature/ERC1271/ownable/index.ts
similarity index 100%
rename from spec/signature/ownable/index.ts
rename to spec/signature/ERC1271/ownable/index.ts
diff --git a/spec/signature/stored/ERC1271Stored.behavior.ts b/spec/signature/ERC1271/stored/ERC1271Stored.behavior.ts
similarity index 100%
rename from spec/signature/stored/ERC1271Stored.behavior.ts
rename to spec/signature/ERC1271/stored/ERC1271Stored.behavior.ts
diff --git a/spec/signature/stored/index.ts b/spec/signature/ERC1271/stored/index.ts
similarity index 100%
rename from spec/signature/stored/index.ts
rename to spec/signature/ERC1271/stored/index.ts
diff --git a/spec/signature/index.ts b/spec/signature/index.ts
index 3913577d..47a0dace 100644
--- a/spec/signature/index.ts
+++ b/spec/signature/index.ts
@@ -1,3 +1 @@
-export * from './base';
-export * from './ownable';
-export * from './stored';
+export * from './ERC1271';
diff --git a/test/signature/ownable/ERC1271Ownable.ts b/test/signature/ERC1271/ownable/ERC1271Ownable.ts
similarity index 100%
rename from test/signature/ownable/ERC1271Ownable.ts
rename to test/signature/ERC1271/ownable/ERC1271Ownable.ts
diff --git a/test/signature/stored/ERC1271Stored.ts b/test/signature/ERC1271/stored/ERC1271Stored.ts
similarity index 100%
rename from test/signature/stored/ERC1271Stored.ts
rename to test/signature/ERC1271/stored/ERC1271Stored.ts
diff --git a/test/signature/ERC7201/ERC7201.ts b/test/signature/ERC7201/ERC7201.ts
new file mode 100644
index 00000000..466fd347
--- /dev/null
+++ b/test/signature/ERC7201/ERC7201.ts
@@ -0,0 +1,23 @@
+import { hashData, signData } from '@solidstate/library';
+import { ERC7201Mock, ERC7201Mock__factory } from '@solidstate/typechain-types';
+import { expect } from 'chai';
+import { ethers } from 'hardhat';
+
+describe('ERC7201', () => {
+  let instance: ERC7201Mock;
+
+  beforeEach(async () => {
+    const [deployer] = await ethers.getSigners();
+    instance = await new ERC7201Mock__factory(deployer).deploy();
+  });
+
+  describe('__internal', () => {
+    describe('#calculateStorageSlot(string)', () => {
+      it('calculates storage slot using "erc7201" formula', async () => {
+        expect(await instance.calculateStorageSlot('example.main')).to.equal(
+          '0x183a6125c38840424c4a85fa12bab2ab606c4b6d0e7cc73c0c06ba5300eab500',
+        );
+      });
+    });
+  });
+});