diff --git a/masque/file/gdsii.py b/masque/file/gdsii.py
index d78f591..fa49eb3 100644
--- a/masque/file/gdsii.py
+++ b/masque/file/gdsii.py
@@ -648,7 +648,7 @@ def check_valid_names(
         logger.error('Names contain invalid characters:\n' + pformat(bad_chars))
 
     if bad_lengths:
-        logger.error(f'Names too long (>{max_length}:\n' + pformat(bad_chars))
+        logger.error(f'Names too long (>{max_length}):\n' + pformat(bad_lengths))
 
     if bad_chars or bad_lengths:
         raise LibraryError('Library contains invalid names, see log above')