diff --git a/frontend/src/components/ai-builder/AIFlowBuilderModal.tsx b/frontend/src/components/ai-builder/AIFlowBuilderModal.tsx
index 939876d2..ba4d2e0a 100644
--- a/frontend/src/components/ai-builder/AIFlowBuilderModal.tsx
+++ b/frontend/src/components/ai-builder/AIFlowBuilderModal.tsx
@@ -37,6 +37,11 @@ export function AIFlowBuilderModal({ isOpen, onClose }: AIFlowBuilderModalProps)
   // Auto-trigger scaffold after conversation starts (ref prevents double-fire)
   const hasTriggeredScaffold = useRef(false)
   useEffect(() => {
+    // Reset guard when wizard resets to foundation (Start Over or close)
+    if (phase === 'foundation') {
+      hasTriggeredScaffold.current = false
+      return
+    }
     if (phase === 'scaffolding' && !hasTriggeredScaffold.current && !useAIFlowBuilderStore.getState().suggestedBranches.length) {
       hasTriggeredScaffold.current = true
       scaffold()