diff --git a/package-lock.json b/package-lock.json
index c15dc61a7..d7edfe1ca 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -7,6 +7,7 @@
     "": {
       "name": "@vscode-elements/elements",
       "version": "1.16.1",
+      "hasInstallScript": true,
       "license": "MIT",
       "dependencies": {
         "lit": "^3.2.1"
@@ -53,7 +54,7 @@
         "rollup-plugin-filesize": "^10.0.0",
         "rollup-plugin-visualizer": "^6.0.0",
         "semver": "^7.7.1",
-        "sinon": "^20.0.0",
+        "sinon": "^21.0.0",
         "ts-lit-plugin": "^2.0.2",
         "typescript": "^5.8.2",
         "wireit": "^0.14.11"
@@ -10555,11 +10556,10 @@
       }
     },
     "node_modules/sinon": {
-      "version": "20.0.0",
-      "resolved": "https://registry.npmjs.org/sinon/-/sinon-20.0.0.tgz",
-      "integrity": "sha512-+FXOAbdnj94AQIxH0w1v8gzNxkawVvNqE3jUzRLptR71Oykeu2RrQXXl/VQjKay+Qnh73fDt/oDfMo6xMeDQbQ==",
+      "version": "21.0.0",
+      "resolved": "https://registry.npmjs.org/sinon/-/sinon-21.0.0.tgz",
+      "integrity": "sha512-TOgRcwFPbfGtpqvZw+hyqJDvqfapr1qUlOizROIk4bBLjlsjlB00Pg6wMFXNtJRpu+eCZuVOaLatG7M8105kAw==",
       "dev": true,
-      "license": "BSD-3-Clause",
       "dependencies": {
         "@sinonjs/commons": "^3.0.1",
         "@sinonjs/fake-timers": "^13.0.5",
@@ -10577,7 +10577,6 @@
       "resolved": "https://registry.npmjs.org/@sinonjs/commons/-/commons-3.0.1.tgz",
       "integrity": "sha512-K3mCHKQ9sVh8o1C9cxkwxaOmXoAMlDxC1mYyHrjqOWEcBjYr76t96zL2zlj5dUGZ3HSw240X1qgH3Mjf1yJWpQ==",
       "dev": true,
-      "license": "BSD-3-Clause",
       "dependencies": {
         "type-detect": "4.0.8"
       }
@@ -10587,7 +10586,6 @@
       "resolved": "https://registry.npmjs.org/@sinonjs/fake-timers/-/fake-timers-13.0.5.tgz",
       "integrity": "sha512-36/hTbH2uaWuGVERyC6da9YwGWnzUZXuPro/F2LfsdOsLnCojz/iSH8MxUt/FD2S5XBSVPhmArFUXcpCQ2Hkiw==",
       "dev": true,
-      "license": "BSD-3-Clause",
       "dependencies": {
         "@sinonjs/commons": "^3.0.1"
       }
@@ -10597,7 +10595,6 @@
       "resolved": "https://registry.npmjs.org/diff/-/diff-7.0.0.tgz",
       "integrity": "sha512-PJWHUb1RFevKCwaFA9RlG5tCd+FO5iRh9A8HEtkmBH2Li03iJriB6m6JIN4rGz3K3JLawI7/veA1xzRKP6ISBw==",
       "dev": true,
-      "license": "BSD-3-Clause",
       "engines": {
         "node": ">=0.3.1"
       }
@@ -19362,9 +19359,9 @@
       }
     },
     "sinon": {
-      "version": "20.0.0",
-      "resolved": "https://registry.npmjs.org/sinon/-/sinon-20.0.0.tgz",
-      "integrity": "sha512-+FXOAbdnj94AQIxH0w1v8gzNxkawVvNqE3jUzRLptR71Oykeu2RrQXXl/VQjKay+Qnh73fDt/oDfMo6xMeDQbQ==",
+      "version": "21.0.0",
+      "resolved": "https://registry.npmjs.org/sinon/-/sinon-21.0.0.tgz",
+      "integrity": "sha512-TOgRcwFPbfGtpqvZw+hyqJDvqfapr1qUlOizROIk4bBLjlsjlB00Pg6wMFXNtJRpu+eCZuVOaLatG7M8105kAw==",
       "dev": true,
       "requires": {
         "@sinonjs/commons": "^3.0.1",
diff --git a/package.json b/package.json
index d1b5b5a77..b027e1e15 100644
--- a/package.json
+++ b/package.json
@@ -176,7 +176,7 @@
     "rollup-plugin-filesize": "^10.0.0",
     "rollup-plugin-visualizer": "^6.0.0",
     "semver": "^7.7.1",
-    "sinon": "^20.0.0",
+    "sinon": "^21.0.0",
     "ts-lit-plugin": "^2.0.2",
     "typescript": "^5.8.2",
     "wireit": "^0.14.11"