diff --git a/app/api/canvas/local-edit/route.ts b/app/api/canvas/local-edit/route.ts
index 6d13207a3..029011f89 100644
--- a/app/api/canvas/local-edit/route.ts
+++ b/app/api/canvas/local-edit/route.ts
@@ -1279,7 +1279,8 @@ export async function POST(request: NextRequest) {
       },
       displayPrompt,
       falSafetyTolerance: useFalScaleAdjustCoordinateGuide ? "6" : undefined,
-      falSystemPrompt: undefined,
+      falSystemPrompt:
+        useFalScaleAdjustCoordinateGuide ? buildFalScaleAdjustSystemPrompt() : undefined,
       falThinkingLevel: undefined,
       allowFailover: useFalScaleAdjustCoordinateGuide ? false : undefined,
       imageCount: 1,