diff --git a/sphinx/highlighting.py b/sphinx/highlighting.py
index 76b657acee6..bb2687a2bc8 100644
--- a/sphinx/highlighting.py
+++ b/sphinx/highlighting.py
@@ -32,7 +32,7 @@
     from pygments.style import Style
 
 if tuple(map(int, pygments.__version__.split('.')))[:2] < (2, 18):
-    from pygments.formatter import Formatter
+    from pygments.formatter import Formatter  # NoQA: F811
 
     Formatter.__class_getitem__ = lambda cls, name: cls  # type: ignore[attr-defined]