diff --git a/sphinx/util/requests.py b/sphinx/util/requests.py
index 09b7a43b1..6834e6368 100644
--- a/sphinx/util/requests.py
+++ b/sphinx/util/requests.py
@@ -41,7 +41,7 @@ try:
 except ImportError:
     try:
         # for Debian-jessie
-        from urllib3.exceptions import InsecurePlatformWarning
+        from urllib3.exceptions import InsecurePlatformWarning  # type: ignore
     except ImportError:
         # for requests < 2.4.0
         InsecurePlatformWarning = None