diff --git a/tuf/ngclient/updater.py b/tuf/ngclient/updater.py
index 7a5b2c25..e518118a 100644
--- a/tuf/ngclient/updater.py
+++ b/tuf/ngclient/updater.py
@@ -183,7 +183,7 @@ def find_cached_target(
 
         Returns:
             Local file path if the file is an up to date target file.
-            None if file is not found or it is not up to date.
+            ``None`` if file is not found or it is not up to date.
         """
 
         if filepath is None: