diff --git a/lib/web_ui/lib/src/engine/skwasm/skwasm_impl/surface.dart b/lib/web_ui/lib/src/engine/skwasm/skwasm_impl/surface.dart
index bce7a8a62edf0..4827c78b00f77 100644
--- a/lib/web_ui/lib/src/engine/skwasm/skwasm_impl/surface.dart
+++ b/lib/web_ui/lib/src/engine/skwasm/skwasm_impl/surface.dart
@@ -78,7 +78,7 @@ class SkwasmSurface {
     return completer.future;
   }
 
-  void _callbackHandler(JSNumber callbackId, JSNumber context, JSAny jsContext) {
+  void _callbackHandler(JSNumber callbackId, JSNumber context, JSAny? jsContext) {
     final Completer<JSAny> completer = _pendingCallbacks.remove(callbackId.toDartInt)!;
     if (jsContext.isUndefinedOrNull) {
       completer.complete(context);
diff --git a/lib/web_ui/skwasm/library_skwasm_support.js b/lib/web_ui/skwasm/library_skwasm_support.js
index d1c3459d10809..c9c1aba46db3e 100644
--- a/lib/web_ui/skwasm/library_skwasm_support.js
+++ b/lib/web_ui/skwasm/library_skwasm_support.js
@@ -39,8 +39,9 @@ mergeInto(LibraryManager.library, {
               object.close();
             }
             associatedObjectsMap.delete(data.pointer);
+            return;
           default:
-            console.warn('unrecognized skwasm message');
+            console.warn(`unrecognized skwasm message: ${skwasmMessage}`);
         }
       };
       if (!threadId) {