diff --git a/trytond/init.sql b/trytond/init.sql
index 71dc53a5e4..90df15b4ec 100644
--- a/trytond/init.sql
+++ b/trytond/init.sql
@@ -7,6 +7,7 @@ CREATE TABLE ir_model (
   model varchar NOT NULL,
   name varchar,
   info text,
+  module varchar,
   primary key(id)
 );
 
diff --git a/trytond/ir/model.py b/trytond/ir/model.py
index 46ad9ab895..a23a695506 100644
--- a/trytond/ir/model.py
+++ b/trytond/ir/model.py
@@ -9,14 +9,20 @@ class Model(OSV):
     "Model"
     _name = 'ir.model'
     _description = __doc__
-    name = fields.Char('Model name', size=None, translate=True)
-    model = fields.Char('Object name', size=None, required=True)
+    name = fields.Char('Model name', translate=True)
+    model = fields.Char('Object name', required=True)
     info = fields.Text('Information')
+    module = fields.Char('Module',
+       help="Module in which this model is defined")
     fields = fields.One2Many('ir.model.field', 'model', 'Fields',
        required=True)
 
-    def default_name(self, cursor, user, context=None):
-        return 'No Name'
+    def __init__(self):
+        super(Model, self).__init__()
+        self._sql_constraints += [
+            ('name_uniq', 'UNIQUE(name)',
+                'The name of model must be unique!'),
+        ]
 
 Model()
 
@@ -24,19 +30,19 @@ class ModelField(OSV):
     "Model field"
     _name = 'ir.model.field'
     _description = __doc__
-    name = fields.Char('Name', size=None, required=True)
-    relation = fields.Char('Model Relation', size=None)
+    name = fields.Char('Name', required=True)
+    relation = fields.Char('Model Relation')
     model = fields.Many2One('ir.model', 'Model', required=True,
        select=True, ondelete='cascade')
-    field_description = fields.Char('Field Description', size=None,
+    field_description = fields.Char('Field Description',
        translate=True)
-    ttype = fields.Char('Field Type', size=None)
+    ttype = fields.Char('Field Type')
     groups = fields.Many2Many('res.group', 'ir_model_field_group_rel',
        'field_id', 'group_id', 'Groups')
-    group_name = fields.Char('Group Name', size=None)
+    group_name = fields.Char('Group Name')
     view_load = fields.Boolean('View Auto-Load')
     help = fields.Text('Help', translate=True)
-    module = fields.Char('Module', size=None,
+    module = fields.Char('Module',
        help="Module in which this field is defined")
 
     def __init__(self):
@@ -160,9 +166,9 @@ class ModelData(OSV):
     _name = 'ir.model.data'
     _description = __doc__
     fs_id = fields.Char('Identifier on File System', required=True,
-       size=None, help="The id of the record as known on the file system.")
-    model = fields.Char('Model', required=True, size=None)
-    module = fields.Char('Module', required=True, size=None)
+            help="The id of the record as known on the file system.")
+    model = fields.Char('Model', required=True)
+    module = fields.Char('Module', required=True)
     db_id = fields.Integer('Resource ID',
        help="The id of the record in the database.")
     date_update = fields.DateTime('Update Date')
diff --git a/trytond/ir/model.xml b/trytond/ir/model.xml
index a7bd2616d9..0768ce24c9 100644
--- a/trytond/ir/model.xml
+++ b/trytond/ir/model.xml
@@ -7,14 +7,16 @@
             <field name="type">form</field>
             <field name="arch" type="xml">
               <![CDATA[
-                <form string="Model Description">
+                <form string="Model Description" col="6">
                     <label name="name"/>
                     <field name="name"/>
                     <label name="model"/>
                     <field name="model"/>
-                    <separator name="info" colspan="4"/>
-                    <field name="info" colspan="4"/>
-                    <field name="fields" colspan="4" readonly="1">
+                    <label name="module"/>
+                    <field name="module"/>
+                    <separator name="info" colspan="6"/>
+                    <field name="info" colspan="6"/>
+                    <field name="fields" colspan="6" readonly="1">
                         <form string="Fields Description">
                             <label name="name"/>
                             <field name="name"/>
@@ -42,6 +44,7 @@
                     <field name="name" select="1"/>
                     <field name="model" select="1"/>
                     <field name="info" select="1"/>
+                    <field name="module" select="1"/>
                 </tree>
                 ]]>
             </field>
diff --git a/trytond/osv/orm.py b/trytond/osv/orm.py
index 5fd2aad098..2dad0462b9 100644
--- a/trytond/osv/orm.py
+++ b/trytond/osv/orm.py
@@ -258,8 +258,9 @@ class ORM(object):
             # reference model in order to have a description
             # of its fonctionnality in custom_report
             cursor.execute("INSERT INTO ir_model " \
-                    "(model, name, info) VALUES (%s, %s, %s)",
-                    (self._name, self._description, self.__doc__))
+                    "(model, name, info, module) VALUES (%s, %s, %s, %s)",
+                    (self._name, self._description, self.__doc__,
+                        module_name))
             cursor.execute("SELECT id FROM ir_model WHERE model = %s",
                     (self._name,))
         (model_id,) = cursor.fetchone()