diff --git a/trytond/model/fields/function.py b/trytond/model/fields/function.py
index be7e5e4e6b..73fb0d9d66 100644
--- a/trytond/model/fields/function.py
+++ b/trytond/model/fields/function.py
@@ -63,7 +63,7 @@ class Function(Field):
 
     def convert_domain(self, domain, tables, Model):
         name, operator, value = domain[:3]
-        assert name == self.name
+        assert name.startswith(self.name)
         method = getattr(Model, 'domain_%s' % name, None)
         if method:
             return method(domain, tables)