diff --git a/samples/langchain_on_vertexai/create_embeddings.py b/samples/langchain_on_vertexai/create_embeddings.py
index 105a86df..9fd5e241 100644
--- a/samples/langchain_on_vertexai/create_embeddings.py
+++ b/samples/langchain_on_vertexai/create_embeddings.py
@@ -33,6 +33,8 @@
 
 
 async def create_databases():
+    PostgresEngine._connector = None
+
     engine = await PostgresEngine.afrom_instance(
         PROJECT_ID,
         REGION,
@@ -49,6 +51,8 @@ async def create_databases():
 
 
 async def create_vectorstore():
+    PostgresEngine._connector = None
+
     engine = await PostgresEngine.afrom_instance(
         PROJECT_ID,
         REGION,
@@ -108,4 +112,16 @@ async def main():
     await create_vectorstore()
 
 
-asyncio.run(main())
+if __name__ == "__main__":
+    loop = asyncio.new_event_loop()
+    asyncio.set_event_loop(loop)
+    try:
+        loop.run_until_complete(main())
+    finally:
+        try:
+            tasks = asyncio.all_tasks(loop)
+            for task in tasks:
+                task.cancel()
+            loop.run_until_complete(asyncio.gather(*tasks, return_exceptions=True))
+        finally:
+            loop.close()
diff --git a/samples/langchain_on_vertexai/requirements.txt b/samples/langchain_on_vertexai/requirements.txt
index f841a4c3..064bf76a 100644
--- a/samples/langchain_on_vertexai/requirements.txt
+++ b/samples/langchain_on_vertexai/requirements.txt
@@ -1,4 +1,4 @@
-google-cloud-aiplatform[reasoningengine,langchain]==1.120.0
+google-cloud-aiplatform[reasoningengine,langchain]==1.121.0
 google-cloud-resource-manager==1.14.2
 langchain-community==0.3.31
 langchain-google-cloud-sql-pg==0.14.1