diff --git a/backend/requirements.txt b/backend/requirements.txt
index 06d1775..5e8c2dc 100644
--- a/backend/requirements.txt
+++ b/backend/requirements.txt
@@ -11,7 +11,7 @@ websockets>=12.0
 httpx>=0.26.0
 
 # LangChain / LangGraph
-langchain>=1.0.0
+langchain>=1.3.6
 langchain-core>=1.0.0
 langchain-google-genai>=2.0.0
 langgraph>=0.6.0