diff --git a/python/dify_plugin/entities/model/llm.py b/python/dify_plugin/entities/model/llm.py
index fe4f7db2..0f8edf05 100644
--- a/python/dify_plugin/entities/model/llm.py
+++ b/python/dify_plugin/entities/model/llm.py
@@ -76,6 +76,7 @@ class LLMResultChunkDelta(BaseModel):
 
     index: int
     message: AssistantPromptMessage
+    reasoning_content: str | None = None
     usage: LLMUsage | None = None
     finish_reason: str | None = None