diff --git a/api/apps/canvas_app.py b/api/apps/canvas_app.py
index 76426f417..8dcbb254c 100644
--- a/api/apps/canvas_app.py
+++ b/api/apps/canvas_app.py
@@ -65,7 +65,7 @@ def save():
     req["dsl"] = json.loads(req["dsl"])
     if "id" not in req:
         if UserCanvasService.query(user_id=current_user.id, title=req["title"].strip()):
-            return get_data_error_result(f"{req['title'].strip()} already exists.")
+            return get_data_error_result(message=f"{req['title'].strip()} already exists.")
         req["id"] = get_uuid()
         if not UserCanvasService.save(**req):
             return get_data_error_result(message="Fail to save canvas.")