diff --git a/lib/import b/lib/import
index d684c05..cbdf167 100755
--- a/lib/import
+++ b/lib/import
@@ -86,9 +86,9 @@ for ldif_path in args.ldifs:
                 if key not in new_attrs:
                     modlist.append((ldap.MOD_DELETE, key, None))
             for key in new_attrs:
+                new = set(new_attrs[key])
                 if key in old_attrs:
                     old = set(old_attrs[key])
-                    new = set(new_attrs[key])
                     if old & new:
                         if old-new:
                             modlist.append((ldap.MOD_DELETE, key, list(old-new)))