diff --git a/openerp/addons/base/ir/ir_model.py b/openerp/addons/base/ir/ir_model.py
index 309ed6e38f6..68ad0509011 100644
--- a/openerp/addons/base/ir/ir_model.py
+++ b/openerp/addons/base/ir/ir_model.py
@@ -113,10 +113,8 @@ class IrModel(models.Model):
             for model in self:
                 if model.state != 'manual':
                     raise UserError(_("Model '%s' contains module data and cannot be removed!") % model.name)
-
-        # prevent screwing up fields that depend on these models' fields
-        for model in self:
-            model.field_id._prepare_update()
+                # prevent screwing up fields that depend on these models' fields
+                model.field_id._prepare_update()
 
         self._drop_table()
         res = super(IrModel, self).unlink()