diff --git a/api/core/workflow/utils/structured_output/prompt.py b/api/core/workflow/utils/structured_output/prompt.py
index 2f0bd3d016..06d9b2056e 100644
--- a/api/core/workflow/utils/structured_output/prompt.py
+++ b/api/core/workflow/utils/structured_output/prompt.py
@@ -1,5 +1,5 @@
 STRUCTURED_OUTPUT_PROMPT = """You’re a helpful AI assistant. You could answer questions and output in JSON format.
-constrant:
+constraints:
     - You must output in JSON format.
     - Do not output boolean value, use string type instead.
     - Do not output integer or float value, use number type instead.