diff --git a/types/webappsec-credential-management/index.d.ts b/types/webappsec-credential-management/index.d.ts
index 9ab3292c3b..ba9058a9a0 100644
--- a/types/webappsec-credential-management/index.d.ts
+++ b/types/webappsec-credential-management/index.d.ts
@@ -25,6 +25,9 @@ interface GlobalFetch {
     // variant for navigator.credentials monkey patching
     fetch(url: Request|string, init?: CMRequestInit): Promise<Response>;
 }
+interface WindowOrWorkerGlobalScope {
+    fetch(url: Request|string, init?: CMRequestInit): Promise<Response>;
+}
 
 /**
  * Variant of TS 2.2 {@link RequestInit} that permits a
diff --git a/types/webappsec-credential-management/webappsec-credential-management-tests.ts b/types/webappsec-credential-management/webappsec-credential-management-tests.ts
index 2afa9f8785..9d20ed37dc 100644
--- a/types/webappsec-credential-management/webappsec-credential-management-tests.ts
+++ b/types/webappsec-credential-management/webappsec-credential-management-tests.ts
@@ -214,7 +214,7 @@ function signOutDeprecated() {
     }
 
     navigator.credentials.requireUserMediation().then(() => {
-        document.location.assign('/');
+        document.location!.assign('/');
     });
 }
 
@@ -224,7 +224,7 @@ function signOut() {
     }
 
     navigator.credentials.preventSilentAccess().then(() => {
-        document.location.assign('/');
+        document.location!.assign('/');
     });
 }