diff --git a/web-components/package-lock.json b/web-components/package-lock.json
index a6e0139d7..e1fcf44d5 100644
--- a/web-components/package-lock.json
+++ b/web-components/package-lock.json
@@ -42,7 +42,7 @@
         "@types/jsonpath": "^0.2.4",
         "@types/node": "^25.9.1",
         "@vitest/browser": "^4.1.11",
-        "happy-dom": "^20.14.0",
+        "happy-dom": "^21.0.4",
         "jsdom": "^29.1.1",
         "typescript": "^6.0.3",
         "vite-plugin-monaco-editor": "^1.1.0",
@@ -3448,9 +3448,9 @@
       }
     },
     "node_modules/happy-dom": {
-      "version": "20.14.0",
-      "resolved": "https://registry.npmjs.org/happy-dom/-/happy-dom-20.14.0.tgz",
-      "integrity": "sha512-4bRh1KzRvKDnFNTlLhzT1RZTpkKhQbQDl9j+7GXszWsvuspYdo29k6OHRf4PwiM6oLb8r/pMWeYiJjkfod5AvQ==",
+      "version": "21.0.4",
+      "resolved": "https://registry.npmjs.org/happy-dom/-/happy-dom-21.0.4.tgz",
+      "integrity": "sha512-tFm+GaLBgo6o0awHnvHaNoraVo27qJ+2tZEtZ+cIa08hXbeitrxAJajLI05hsUy/2/YTKcUjQYzHe5mCcraLBw==",
       "dev": true,
       "license": "MIT",
       "dependencies": {
diff --git a/web-components/package.json b/web-components/package.json
index 6a8161c0d..eaaeb970c 100644
--- a/web-components/package.json
+++ b/web-components/package.json
@@ -55,7 +55,7 @@
     "@types/jsonpath": "^0.2.4",
     "@types/node": "^25.9.1",
     "@vitest/browser": "^4.1.11",
-    "happy-dom": "^20.14.0",
+    "happy-dom": "^21.0.4",
     "jsdom": "^29.1.1",
     "typescript": "^6.0.3",
     "vite-plugin-monaco-editor": "^1.1.0",