diff --git a/a2a/weather_service/pyproject.toml b/a2a/weather_service/pyproject.toml
index b6bd6e99..2988b9d0 100644
--- a/a2a/weather_service/pyproject.toml
+++ b/a2a/weather_service/pyproject.toml
@@ -11,7 +11,7 @@ requires-python = ">=3.11"
 dependencies = [
     "a2a-sdk>=0.2.16",
     "langgraph>=1.1.3",
-    "langchain-core>=1.2.11",
+    "langchain-core>=1.2.31",
     "langchain-community>=0.3.27",
     "langchain-ollama>=0.2.1",
     "langchain-openai>=0.3.7",