diff --git a/libs/langchain/langchain/utilities/pubmed.py b/libs/langchain/langchain/utilities/pubmed.py
index 9400d2082a5..06e241d3917 100644
--- a/libs/langchain/langchain/utilities/pubmed.py
+++ b/libs/langchain/langchain/utilities/pubmed.py
@@ -2,6 +2,7 @@ import json
 import logging
 import time
 import urllib.error
+import urllib.parse
 import urllib.request
 from typing import Any, Dict, Iterator, List