diff --git a/package-lock.json b/package-lock.json
index 9458c0347..59f54e998 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -44,7 +44,7 @@
         "@types/node": "24.10.0",
         "@types/react": "19.2.7",
         "@types/react-dom": "19.2.3",
-        "@types/sinon": "17.0.4",
+        "@types/sinon": "21.0.0",
         "@types/sinon-chai": "4.0.0",
         "@web/test-runner": "0.20.2",
         "@web/test-runner-playwright": "0.11.1",
@@ -5567,9 +5567,9 @@
       "license": "MIT"
     },
     "node_modules/@types/sinon": {
-      "version": "17.0.4",
-      "resolved": "https://registry.npmjs.org/@types/sinon/-/sinon-17.0.4.tgz",
-      "integrity": "sha512-RHnIrhfPO3+tJT0s7cFaXGZvsL4bbR3/k7z3P312qMS4JaS2Tk+KiwiLx1S0rQ56ERj00u1/BtdyVd0FY+Pdew==",
+      "version": "21.0.0",
+      "resolved": "https://registry.npmjs.org/@types/sinon/-/sinon-21.0.0.tgz",
+      "integrity": "sha512-+oHKZ0lTI+WVLxx1IbJDNmReQaIsQJjN2e7UUrJHEeByG7bFeKJYsv1E75JxTQ9QKJDp21bAa/0W2Xo4srsDnw==",
       "dev": true,
       "license": "MIT",
       "dependencies": {
diff --git a/package.json b/package.json
index d991a85c8..053a237b4 100644
--- a/package.json
+++ b/package.json
@@ -124,7 +124,7 @@
     "@types/node": "24.10.0",
     "@types/react": "19.2.7",
     "@types/react-dom": "19.2.3",
-    "@types/sinon": "17.0.4",
+    "@types/sinon": "21.0.0",
     "@types/sinon-chai": "4.0.0",
     "@web/test-runner": "0.20.2",
     "@web/test-runner-playwright": "0.11.1",