diff --git a/.github/workflows/lint.yml b/.github/workflows/lint.yml
index 744b7987..4625447d 100644
--- a/.github/workflows/lint.yml
+++ b/.github/workflows/lint.yml
@@ -20,7 +20,7 @@ jobs:
     - name: Set up HLint
       uses: haskell-actions/hlint-setup@v2
       with:
-        version: "3.6.1"
+        version: "3.8"
     - name: Apply HLint
       run: |
         set -ex
diff --git a/.github/workflows/stan.yml b/.github/workflows/stan.yml
index 33ce8a41..809e830b 100644
--- a/.github/workflows/stan.yml
+++ b/.github/workflows/stan.yml
@@ -14,10 +14,10 @@ jobs:
       uses: actions/checkout@v4
 
     - name: Cache dependencies
-      uses: actions/cache@v3
+      uses: actions/cache@v4
       with:
         path: ~/.stack
-        key: ${{ runner.os }}-${{ hashFiles('stack.yaml') }}
+        key: ${{ runner.os }}-${{ runner.arch }}-${{ hashFiles('stack.yaml') }}
 
     - name: Install stan
       run: |
@@ -33,7 +33,7 @@ jobs:
       run: .bin/stan report --cabal-file-path=pantry.cabal
 
     - name: Upload HTML report
-      uses: actions/upload-artifact@v3
+      uses: actions/upload-artifact@v4
       with:
         name: Stan_report
         path: stan.html
diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index 73ccfa7a..d8c664fe 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -7,8 +7,8 @@ on:
     - master
   workflow_dispatch:
 
-# As of 6 January 2024, ubuntu-latest, windows-latest and macos-latest come
-# with Stack 2.13.1.
+# As of 4 February 2024, ubuntu-latest, windows-latest and macos-latest come
+# with Stack 2.13.1. However, macos-14 does not come with Haskell tools.
 
 jobs:
   build:
@@ -21,11 +21,14 @@ jobs:
         - ubuntu-latest
         resolver:
         - stack-ghc-9.4.8.yaml
-        - stack-ghc-9.6.3.yaml
+        - stack-ghc-9.6.4.yaml
         - stack-ghc-9.8.1.yaml
         include:
         - os: macos-latest
           resolver: stack-ghc-9.8.1.yaml
+        # macos-14 provides macOS/AArch64 (M1)
+        - os: macos-14
+          resolver: stack-ghc-9.8.1.yaml
         - os: windows-latest
           resolver: stack-ghc-9.8.1.yaml
     steps:
@@ -33,22 +36,29 @@ jobs:
       uses: actions/checkout@v4
     - name: Cache dependencies on Unix-like OS
       if: startsWith(runner.os, 'Linux') || startsWith(runner.os, 'macOS')
-      uses: actions/cache@v3
+      uses: actions/cache@v4
       with:
         path: ~/.stack
-        key: ${{ runner.os }}-${{ matrix.resolver }}
+        key: ${{ runner.os }}-${{ runner.arch }}-${{ matrix.resolver }}
     - name: Cache dependencies on Windows
       if: startsWith(runner.os, 'Windows')
-      uses: actions/cache@v3
+      uses: actions/cache@v4
       with:
         path: |
            ~\AppData\Roaming\stack
            ~\AppData\Local\Programs\stack
-        key: ${{ runner.os }}-${{ matrix.resolver }}
+        key: ${{ runner.os }}-${{ runner.arch }}-${{ matrix.resolver }}
     - name: Build and run tests
       shell: bash
       run: |
         set -ex
+
+        if [[ "${{ matrix.os }}" == "macos-14" ]]
+        then
+          # macos-14 does not include Haskell tools as at 2024-02-04.
+          curl -sSL https://get.haskellstack.org/ | sh
+        fi
+
         stack --resolver ${{ matrix.resolver }} test --bench --no-run-benchmarks --haddock --no-haddock-deps
   test-pretty-exceptions:
     name: Test build of test-pretty-exceptions
@@ -66,18 +76,18 @@ jobs:
       uses: actions/checkout@v4
     - name: Cache dependencies on Unix-like OS
       if: startsWith(runner.os, 'Linux') || startsWith(runner.os, 'macOS')
-      uses: actions/cache@v3
+      uses: actions/cache@v4
       with:
         path: ~/.stack
-        key: ${{ runner.os }}-${{ matrix.resolver }}-pretty
+        key: ${{ runner.os }}-${{ runner.arch }}-${{ matrix.resolver }}-pretty
     - name: Cache dependencies on Windows
       if: startsWith(runner.os, 'Windows')
-      uses: actions/cache@v3
+      uses: actions/cache@v4
       with:
         path: |
            ~\AppData\Roaming\stack
            ~\AppData\Local\Programs\stack
-        key: ${{ runner.os }}-${{ matrix.resolver }}-pretty
+        key: ${{ runner.os }}-${{ runner.arch }}-${{ matrix.resolver }}-pretty
     - name: Build test-pretty-exceptions
       shell: bash
       run: |
diff --git a/.hlint.yaml b/.hlint.yaml
index ee70d74f..094bbc12 100644
--- a/.hlint.yaml
+++ b/.hlint.yaml
@@ -7,3 +7,7 @@
     name: "Use fewer imports"
     within:
     - Pantry.Types
+- ignore:
+    name: "Functor law"
+    within:
+    - Pantry.Types
diff --git a/stack-ghc-9.2.8.yaml b/stack-ghc-9.2.8.yaml
index 036cce35..55962672 100644
--- a/stack-ghc-9.2.8.yaml
+++ b/stack-ghc-9.2.8.yaml
@@ -1,5 +1,5 @@
 # Snapshot specification for GHC 9.2.8.
-resolver: lts-20.26 # GHC 9.2.8
+snapshot: lts-20.26 # GHC 9.2.8
 
 packages:
 - aeson-warning-parser-0.1.1@sha256:e5b81492d39bfe5de99fdc838e54e0fc0f2e290eb9fcfd4531cabf24baeada76,1353
diff --git a/stack-ghc-9.4.8.yaml b/stack-ghc-9.4.8.yaml
index 9e8062ff..de12e2e0 100644
--- a/stack-ghc-9.4.8.yaml
+++ b/stack-ghc-9.4.8.yaml
@@ -1,5 +1,5 @@
 # Snapshot specification for GHC 9.4.8.
-resolver: lts-21.25 # GHC 9.4.8
+snapshot: lts-21.25 # GHC 9.4.8
 
 packages:
 - aeson-warning-parser-0.1.1@sha256:e5b81492d39bfe5de99fdc838e54e0fc0f2e290eb9fcfd4531cabf24baeada76,1353
diff --git a/stack-ghc-9.6.3.yaml b/stack-ghc-9.6.3.yaml
deleted file mode 100644
index 7804e589..00000000
--- a/stack-ghc-9.6.3.yaml
+++ /dev/null
@@ -1,6 +0,0 @@
-# Snapshot specification for GHC 9.6.3.
-resolver: lts-22.6 # GHC 9.6.3
-
-flags:
-  hackage-security:
-    cabal-syntax: true
diff --git a/stack-ghc-9.6.4.yaml b/stack-ghc-9.6.4.yaml
new file mode 100644
index 00000000..bebfb366
--- /dev/null
+++ b/stack-ghc-9.6.4.yaml
@@ -0,0 +1,6 @@
+# Snapshot specification for GHC 9.6.4.
+snapshot: lts-22.9 # GHC 9.6.4
+
+flags:
+  hackage-security:
+    cabal-syntax: true
diff --git a/stack-ghc-9.8.1.yaml b/stack-ghc-9.8.1.yaml
index 071f6086..023cf7d5 100644
--- a/stack-ghc-9.8.1.yaml
+++ b/stack-ghc-9.8.1.yaml
@@ -1,5 +1,5 @@
 # Snapshot specification for GHC 9.8.1.
-resolver: nightly-2024-01-17 # GHC 9.8.1
+snapshot: nightly-2024-02-04 # GHC 9.8.1
 
 packages:
 - hedgehog-1.4@sha256:47633efec27b49fe5a21d51f3b9fce428ca4b945d39eaa163b2b6a1d3e1465be,4724
diff --git a/stack.yaml b/stack.yaml
index 81cd7970..c0fbaec4 100644
--- a/stack.yaml
+++ b/stack.yaml
@@ -1 +1 @@
-resolver: stack-ghc-9.6.3.yaml
+snapshot: stack-ghc-9.6.4.yaml
diff --git a/stack.yaml.lock b/stack.yaml.lock
index 1b74b0a3..74ebb5da 100644
--- a/stack.yaml.lock
+++ b/stack.yaml.lock
@@ -6,7 +6,7 @@
 packages: []
 snapshots:
 - completed:
-    sha256: 1b4c2669e26fa828451830ed4725e4d406acc25a1fa24fcc039465dd13d7a575
-    size: 714100
-    url: https://raw.githubusercontent.com/commercialhaskell/stackage-snapshots/master/lts/22/6.yaml
-  original: lts-22.6
+    sha256: ad2884d5d84ed4ea576897103606212da3be693eef30591efe2d8d2965895500
+    size: 714105
+    url: https://raw.githubusercontent.com/commercialhaskell/stackage-snapshots/master/lts/22/9.yaml
+  original: lts-22.9