diff --git a/tests/global.d.ts b/tests/global.d.ts
index c6eef78..4c10c61 100644
--- a/tests/global.d.ts
+++ b/tests/global.d.ts
@@ -1,3 +1,11 @@
-interface Window {
-  __registeredTools?: any[];
+import {ModelContext} from '../src/webmcp_types';
+
+declare global {
+  interface Window {
+    __registeredTools?: any[];
+  }
+
+  interface Navigator {
+    modelContext?: ModelContext;
+  }
 }