diff --git a/doc/source/conf.py b/doc/source/conf.py
index 909bd5a80b76e..5534700f0734a 100644
--- a/doc/source/conf.py
+++ b/doc/source/conf.py
@@ -78,7 +78,7 @@
               ]
 
 try:
-    import sphinxcontrib.spelling
+    import sphinxcontrib.spelling  # noqa
 except ImportError as err:
     logger.warn(('sphinxcontrib.spelling failed to import with error "{}". '
                 '`spellcheck` command is not available.'.format(err)))