diff --git a/mat2 b/mat2
index e73c4986a7afa35d57ef5106ae7cbf08f29c0170..4773c85117aec1d2570afc35c96a7833e23f674c 100755
--- a/mat2
+++ b/mat2
@@ -117,7 +117,7 @@ def clean_meta(filename: str, is_lightweight: bool, policy: UnknownMemberPolicy)
     p.lightweight_cleaning = is_lightweight
 
     try:
-        logging.debug('Cleaning %s…' % filename)
+        logging.debug('Cleaning %s…', filename)
         return p.remove_all()
     except RuntimeError as e:
         print("[-] %s can't be cleaned: %s" % (filename, e))