diff --git a/mopidy/local/commands.py b/mopidy/local/commands.py
index 1e7839a5..a0dc23d1 100644
--- a/mopidy/local/commands.py
+++ b/mopidy/local/commands.py
@@ -70,7 +70,6 @@ class ScanCommand(commands.Command):
 
         library = _get_library(args, config)
 
-        uris_in_library = set()
         uris_to_update = set()
         uris_to_remove = set()
 
@@ -87,7 +86,7 @@ class ScanCommand(commands.Command):
                 logger.debug('Missing file %s', track.uri)
                 uris_to_remove.add(track.uri)
             elif mtime > track.last_modified:
-                uris_in_library.add(track.uri)
+                uris_to_update.add(track.uri)
 
         logger.info('Removing %d missing tracks.', len(uris_to_remove))
         for uri in uris_to_remove: