diff --git a/frontend/package-lock.json b/frontend/package-lock.json
index d76d36a..09b341b 100644
--- a/frontend/package-lock.json
+++ b/frontend/package-lock.json
@@ -14,7 +14,7 @@
       "devDependencies": {
         "@types/d3": "^7.4.3",
         "@vitest/coverage-v8": "^4.1.11",
-        "happy-dom": "^20.13.1",
+        "happy-dom": "^21.0.4",
         "typescript": "^7.0.2",
         "vite": "^8.2.1",
         "vitest": "^4.1.11"
@@ -1773,9 +1773,9 @@
       }
     },
     "node_modules/happy-dom": {
-      "version": "20.13.1",
-      "resolved": "https://registry.npmjs.org/happy-dom/-/happy-dom-20.13.1.tgz",
-      "integrity": "sha512-hoh0Sq+2vSDi8CJaFnLBLAlEK7/vrRmUiim30PwFj9aiVwqF/Z+6cCpmt9gNuQgu+PHjNC4O2PhjxA9Nr+UlBQ==",
+      "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/frontend/package.json b/frontend/package.json
index 1aab789..c45a484 100644
--- a/frontend/package.json
+++ b/frontend/package.json
@@ -17,7 +17,7 @@
   "devDependencies": {
     "@types/d3": "^7.4.3",
     "@vitest/coverage-v8": "^4.1.11",
-    "happy-dom": "^20.13.1",
+    "happy-dom": "^21.0.4",
     "typescript": "^7.0.2",
     "vite": "^8.2.1",
     "vitest": "^4.1.11"