diff --git a/samples/index_tuning_sample/requirements.txt b/samples/index_tuning_sample/requirements.txt
index ae3829b0..78483d2a 100644
--- a/samples/index_tuning_sample/requirements.txt
+++ b/samples/index_tuning_sample/requirements.txt
@@ -1,3 +1,3 @@
 langchain-google-alloydb-pg==0.15.0
-langchain==1.3.4
+langchain==1.3.9
 langchain-google-vertexai==3.2.3