diff --git a/apps/ai-game-creator-shell/src/view/ui-editor/useUiEditorPage.ts b/apps/ai-game-creator-shell/src/view/ui-editor/useUiEditorPage.ts
index 850aa498b..42678d63e 100644
--- a/apps/ai-game-creator-shell/src/view/ui-editor/useUiEditorPage.ts
+++ b/apps/ai-game-creator-shell/src/view/ui-editor/useUiEditorPage.ts
@@ -1045,7 +1045,7 @@ export function useUiEditorSession(
   }
 
   async function runSeparationWorkflow() {
-    if (!resourceId) return;
+    if (!resourceId || isWorkflowBusy) return;
     setIsSeparating(true);
     setSeparationStatus(null);
     setCompletionNotice(null);