diff --git a/xontrib/skim.py b/xontrib/skim.py
index 907d1ea..5c748e3 100644
--- a/xontrib/skim.py
+++ b/xontrib/skim.py
@@ -458,7 +458,7 @@ def skip(func):
         return bindings.add( key_def)
     elif key_user is False:    # exists and disabled → don't bind
       return skip
-    else:                      # remove whitespace
+    elif type(key_user) == str:# remove whitespace
       key_user = re_despace.sub('',key_user)
 
     key_user = _parse_key_user(key_user)