diff --git a/adminsortable/admin.py b/adminsortable/admin.py
index 78609a5..7d65cb5 100644
--- a/adminsortable/admin.py
+++ b/adminsortable/admin.py
@@ -99,7 +99,7 @@ class SortableAdmin(SortableAdminBase, ModelAdmin):
         order can be changed via drag-and-drop.
         """
         opts = self.model._meta
-        has_perm = request.user.has_perm('{}.{}'.format(opts.app_label,
+        has_perm = request.user.has_perm('{0}.{1}'.format(opts.app_label,
             opts.get_change_permission()))
 
         objects = self.queryset(request)