diff --git a/samples/index_tuning_sample/requirements.txt b/samples/index_tuning_sample/requirements.txt
index c6036148..81f4e9ba 100644
--- a/samples/index_tuning_sample/requirements.txt
+++ b/samples/index_tuning_sample/requirements.txt
@@ -1,3 +1,3 @@
 langchain-google-alloydb-pg==0.13.0
 langchain==1.1.0
-langchain-google-vertexai==3.1.0
+langchain-google-vertexai==3.1.1