diff --git a/category.py b/category.py
index 471199da7a..1dcae09723 100644
--- a/category.py
+++ b/category.py
@@ -73,6 +73,6 @@ class Category(ModelSQL, ModelView):
             ids = self.search(domain, order=[])
             return [('id', 'in', ids)]
         #TODO Handle list
-        return [('name',) + clause[1:]]
+        return [('name',) + tuple(clause[1:])]
 
 Category()