diff --git a/openerp/addons/base/ir/ir_model.py b/openerp/addons/base/ir/ir_model.py
index e29b44f0678..f78994943f6 100644
--- a/openerp/addons/base/ir/ir_model.py
+++ b/openerp/addons/base/ir/ir_model.py
@@ -200,6 +200,8 @@ class ir_model(osv.osv):
     def instanciate(self, cr, user, model, context=None):
         class x_custom_model(osv.osv):
             _custom = True
+        if isinstance(model, unicode):
+            model = model.encode('utf-8')
         x_custom_model._name = model
         x_custom_model._module = False
         a = x_custom_model._build_model(self.pool, cr)