diff --git a/Libraries/LibWeb/Forward.h b/Libraries/LibWeb/Forward.h
index 33c75c8a8a..6c29afdb08 100644
--- a/Libraries/LibWeb/Forward.h
+++ b/Libraries/LibWeb/Forward.h
@@ -921,6 +921,7 @@ class IDBRequest;
 class IDBTransaction;
 class IDBVersionChangeEvent;
 class Index;
+class Key;
 class ObjectStore;
 class RequestList;