diff --git a/category.py b/category.py
index 87d5404f9a..db5df4c222 100644
--- a/category.py
+++ b/category.py
@@ -16,7 +16,7 @@ class Category(ModelSQL, ModelView):
     def __init__(self):
         super(Category, self).__init__()
         self._order.insert(0, ('name', 'ASC'))
-        
+
         self._constraints += [
             ('check_recursion', 'recursive_categories'),
         ]