diff --git a/src/langchain_google_cloud_sql_pg/engine.py b/src/langchain_google_cloud_sql_pg/engine.py
index 1fc30815..e5a872a1 100644
--- a/src/langchain_google_cloud_sql_pg/engine.py
+++ b/src/langchain_google_cloud_sql_pg/engine.py
@@ -416,7 +416,7 @@ def _run_as_sync(self, coro: Awaitable[T]) -> T:
 
     async def close(self) -> None:
         """Dispose of connection pool"""
-        await self._pool.dispose()
+        await self._run_as_async(self._pool.dispose())
 
     async def _ainit_vectorstore_table(
         self,