diff --git a/dom/notification/Notification.cpp b/dom/notification/Notification.cpp
index 9a7c833794..5439a4fe59 100644
--- a/dom/notification/Notification.cpp
+++ b/dom/notification/Notification.cpp
@@ -1688,6 +1688,11 @@ Notification::GetPermissionInternal(nsISupports* aGlobal, ErrorResult& aRv)
   }
 
   nsCOMPtr<nsIPrincipal> principal = sop->GetPrincipal();
+  if (!principal) {
+    aRv.Throw(NS_ERROR_UNEXPECTED);
+    return NotificationPermission::Denied;
+  }
+
   return GetPermissionInternal(principal, aRv);
 }