diff --git a/package-lock.json b/package-lock.json
index 1538447..1e345b7 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -73,6 +73,7 @@
         "@types/react-dom": "^19.2.3",
         "@types/shell-quote": "^1.7.5",
         "@types/uuid": "^10.0.0",
+        "@types/ws": "^8.18.1",
         "@vitejs/plugin-react": "^4.3.4",
         "@vitest/ui": "^4.0.15",
         "autoprefixer": "^10.4.20",
@@ -4389,6 +4390,16 @@
       "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/@typescript-eslint/eslint-plugin": {
       "version": "8.48.0",
       "resolved": "https://registry.npmjs.org/@typescript-eslint/eslint-plugin/-/eslint-plugin-8.48.0.tgz",
diff --git a/package.json b/package.json
index 46d704a..8320d18 100644
--- a/package.json
+++ b/package.json
@@ -81,6 +81,7 @@
     "@types/react-dom": "^19.2.3",
     "@types/shell-quote": "^1.7.5",
     "@types/uuid": "^10.0.0",
+    "@types/ws": "^8.18.1",
     "@vitejs/plugin-react": "^4.3.4",
     "@vitest/ui": "^4.0.15",
     "autoprefixer": "^10.4.20",
diff --git a/src/test/setup.ts b/src/test/setup.ts
index fb2c703..cc8847a 100644
--- a/src/test/setup.ts
+++ b/src/test/setup.ts
@@ -9,5 +9,4 @@ import "fake-indexeddb/auto";
 
 // Polyfill WebSocket - required by nostr-tools relay code
 import { WebSocket } from "ws";
-// @ts-expect-error - polyfilling global WebSocket for Node.js
-globalThis.WebSocket = WebSocket;
+globalThis.WebSocket = WebSocket as unknown as typeof globalThis.WebSocket;