diff --git a/package-lock.json b/package-lock.json
index c9aa050..dbf56a5 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -10,7 +10,7 @@
       "license": "MIT",
       "devDependencies": {
         "@types/node": "^24.5.2",
-        "happy-dom": "^18.0.1",
+        "happy-dom": "^20.8.9",
         "tsx": "^4.20.5",
         "typescript": "^5.9.2"
       },
@@ -477,6 +477,29 @@
       "dev": true,
       "license": "MIT"
     },
+    "node_modules/@types/ws": {
+      "version": "8.18.1",
+      "resolved": "https://registry.npmjs.org/@types/ws/-/ws-8.18.1.tgz",
+      "integrity": "sha512-ThVF6DCVhA8kUGy+aazFQ4kXQ7E1Ty7A3ypFOe0IcJV8O/M511G99AW24irKrW56Wt44yG9+ij8FaqoBGkuBXg==",
+      "dev": true,
+      "license": "MIT",
+      "dependencies": {
+        "@types/node": "*"
+      }
+    },
+    "node_modules/entities": {
+      "version": "7.0.1",
+      "resolved": "https://registry.npmjs.org/entities/-/entities-7.0.1.tgz",
+      "integrity": "sha512-TWrgLOFUQTH994YUyl1yT4uyavY5nNB5muff+RtWaqNVCAK408b5ZnnbNAUEWLTCpum9w6arT70i1XdQ4UeOPA==",
+      "dev": true,
+      "license": "BSD-2-Clause",
+      "engines": {
+        "node": ">=0.12"
+      },
+      "funding": {
+        "url": "https://github.com/fb55/entities?sponsor=1"
+      }
+    },
     "node_modules/esbuild": {
       "version": "0.27.4",
       "resolved": "https://registry.npmmirror.com/esbuild/-/esbuild-0.27.4.tgz",
@@ -548,37 +571,23 @@
       }
     },
     "node_modules/happy-dom": {
-      "version": "18.0.1",
-      "resolved": "https://registry.npmmirror.com/happy-dom/-/happy-dom-18.0.1.tgz",
-      "integrity": "sha512-qn+rKOW7KWpVTtgIUi6RVmTBZJSe2k0Db0vh1f7CWrWclkkc7/Q+FrOfkZIb2eiErLyqu5AXEzE7XthO9JVxRA==",
+      "version": "20.8.9",
+      "resolved": "https://registry.npmjs.org/happy-dom/-/happy-dom-20.8.9.tgz",
+      "integrity": "sha512-Tz23LR9T9jOGVZm2x1EPdXqwA37G/owYMxRwU0E4miurAtFsPMQ1d2Jc2okUaSjZqAFz2oEn3FLXC5a0a+siyA==",
       "dev": true,
       "license": "MIT",
       "dependencies": {
-        "@types/node": "^20.0.0",
+        "@types/node": ">=20.0.0",
         "@types/whatwg-mimetype": "^3.0.2",
-        "whatwg-mimetype": "^3.0.0"
+        "@types/ws": "^8.18.1",
+        "entities": "^7.0.1",
+        "whatwg-mimetype": "^3.0.0",
+        "ws": "^8.18.3"
       },
       "engines": {
         "node": ">=20.0.0"
       }
     },
-    "node_modules/happy-dom/node_modules/@types/node": {
-      "version": "20.19.37",
-      "resolved": "https://registry.npmmirror.com/@types/node/-/node-20.19.37.tgz",
-      "integrity": "sha512-8kzdPJ3FsNsVIurqBs7oodNnCEVbni9yUEkaHbgptDACOPW04jimGagZ51E6+lXUwJjgnBw+hyko/lkFWCldqw==",
-      "dev": true,
-      "license": "MIT",
-      "dependencies": {
-        "undici-types": "~6.21.0"
-      }
-    },
-    "node_modules/happy-dom/node_modules/undici-types": {
-      "version": "6.21.0",
-      "resolved": "https://registry.npmmirror.com/undici-types/-/undici-types-6.21.0.tgz",
-      "integrity": "sha512-iwDZqg0QAGrg9Rav5H4n0M64c3mkR59cJ6wQp+7C4nI0gsmExaedaYLNO44eT4AtBBwjbTiGPMlt2Md0T9H9JQ==",
-      "dev": true,
-      "license": "MIT"
-    },
     "node_modules/resolve-pkg-maps": {
       "version": "1.0.0",
       "resolved": "https://registry.npmmirror.com/resolve-pkg-maps/-/resolve-pkg-maps-1.0.0.tgz",
@@ -639,6 +648,28 @@
       "engines": {
         "node": ">=12"
       }
+    },
+    "node_modules/ws": {
+      "version": "8.20.0",
+      "resolved": "https://registry.npmjs.org/ws/-/ws-8.20.0.tgz",
+      "integrity": "sha512-sAt8BhgNbzCtgGbt2OxmpuryO63ZoDk/sqaB/znQm94T4fCEsy/yV+7CdC1kJhOU9lboAEU7R3kquuycDoibVA==",
+      "dev": true,
+      "license": "MIT",
+      "engines": {
+        "node": ">=10.0.0"
+      },
+      "peerDependencies": {
+        "bufferutil": "^4.0.1",
+        "utf-8-validate": ">=5.0.2"
+      },
+      "peerDependenciesMeta": {
+        "bufferutil": {
+          "optional": true
+        },
+        "utf-8-validate": {
+          "optional": true
+        }
+      }
     }
   }
 }
diff --git a/package.json b/package.json
index e43700e..eba64dd 100644
--- a/package.json
+++ b/package.json
@@ -42,7 +42,7 @@
   "license": "MIT",
   "devDependencies": {
     "@types/node": "^24.5.2",
-    "happy-dom": "^18.0.1",
+    "happy-dom": "^20.8.9",
     "tsx": "^4.20.5",
     "typescript": "^5.9.2"
   }