diff --git a/package-lock.json b/package-lock.json
index 329886d..1c39568 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -15,7 +15,6 @@
       "devDependencies": {
         "@google-cloud/kms": "^4.0.1",
         "@types/chai": "^4.3.6",
-        "@types/google-cloud__kms": "^1.5.4",
         "@types/mocha": "^10.0.1",
         "@types/node": "^20.5.9",
         "@typescript-eslint/eslint-plugin": "^6.6.0",
@@ -40,7 +39,7 @@
         "node": ">=18.16.0"
       },
       "optionalDependencies": {
-        "@google-cloud/kms": "^3.6.0"
+        "@google-cloud/kms": "^4.0.1"
       }
     },
     "node_modules/@aashutoshrathi/word-wrap": {
@@ -1158,22 +1157,6 @@
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       "dev": true
     },
-    "node_modules/@types/google-cloud__kms": {
-      "version": "1.5.4",
-      "resolved": "https://registry.npmjs.org/@types/google-cloud__kms/-/google-cloud__kms-1.5.4.tgz",
-      "integrity": "sha512-4CqJbKOigBcw/Qw4V3Ecia67OGO9m8WdUiNy+CGPgSp0l6ps+x+2KaHCqVXbd6o9R7U0EMEys4jlTYIWHrUM0w==",
-      "dev": true,
-      "dependencies": {
-        "@types/google-protobuf": "*",
-        "@types/node": "*"
-      }
-    },
-    "node_modules/@types/google-protobuf": {
-      "version": "3.15.6",
-      "resolved": "https://registry.npmjs.org/@types/google-protobuf/-/google-protobuf-3.15.6.tgz",
-      "integrity": "sha512-pYVNNJ+winC4aek+lZp93sIKxnXt5qMkuKmaqS3WGuTq0Bw1ZDYNBgzG5kkdtwcv+GmYJGo3yEg6z2cKKAiEdw==",
-      "dev": true
-    },
     "node_modules/@types/json-schema": {
       "version": "7.0.12",
       "resolved": "https://registry.npmjs.org/@types/json-schema/-/json-schema-7.0.12.tgz",
diff --git a/package.json b/package.json
index 6d9f1a6..7053b3d 100644
--- a/package.json
+++ b/package.json
@@ -30,7 +30,6 @@
   "devDependencies": {
     "@google-cloud/kms": "^4.0.1",
     "@types/chai": "^4.3.6",
-    "@types/google-cloud__kms": "^1.5.4",
     "@types/mocha": "^10.0.1",
     "@types/node": "^20.5.9",
     "@typescript-eslint/eslint-plugin": "^6.6.0",
@@ -56,6 +55,6 @@
     "lodash": "^4.17.21"
   },
   "optionalDependencies": {
-    "@google-cloud/kms": "^3.6.0"
+    "@google-cloud/kms": "^4.0.1"
   }
 }