diff --git a/requirements.txt b/requirements.txt
index b561ebc..4c86e0b 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,7 +1,7 @@
 # Core dependencies - pinned to specific versions for fast, reliable installs
 pydantic==2.13.4
 langchain-core==1.3.3
-langchain==1.2.18
+langchain==1.3.9
 langchain-openai==1.2.1
 langchain-anthropic==1.4.3
 langchain-google-genai==4.2.2
diff --git a/setup.py b/setup.py
index 3900f5b..57915e8 100644
--- a/setup.py
+++ b/setup.py
@@ -26,7 +26,7 @@
     install_requires=[
         "pydantic==2.13.4",
         "langchain-core==1.3.3",
-        "langchain==1.2.18",
+        "langchain==1.3.9",
         "langchain-openai==1.2.1",
         "langchain-anthropic==1.4.3",
         "langchain-google-genai==4.2.2",