diff --git a/addons/portal/portal.py b/addons/portal/portal.py
index bbab8b16cd3..d94e541eb03 100644
--- a/addons/portal/portal.py
+++ b/addons/portal/portal.py
@@ -30,10 +30,3 @@ class portal(osv.osv):
     _columns = {
         'is_portal': fields.boolean('Portal', help="If checked, this group is usable as a portal."),
     }
-
-class res_users(osv.Model):
-    _inherit = 'res.users'
-    def _signup_create_user(self, cr, uid, values, context=None):
-    	values['share'] = True
-    	return super(res_users, self)._signup_create_user(cr, uid, values, context=context)
-
diff --git a/addons/portal/portal_data.xml b/addons/portal/portal_data.xml
index 35dee070c71..273d1a8c463 100644
--- a/addons/portal/portal_data.xml
+++ b/addons/portal/portal_data.xml
@@ -6,9 +6,6 @@
         <record id="base.group_portal" model="res.groups">
             <field name="is_portal" eval="True"/>
         </record>
-        <record id="auth_signup.default_template_user" model="res.users">
-            <field name="share" eval="True"/>
-        </record>
 
     </data>
 </openerp>
diff --git a/addons/portal/portal_demo.xml b/addons/portal/portal_demo.xml
index 3abc9c8cef5..f6e46708bbc 100644
--- a/addons/portal/portal_demo.xml
+++ b/addons/portal/portal_demo.xml
@@ -22,7 +22,6 @@
 Mr Demo Portal</field>
             <!-- Avoid auto-including this user in any default group -->
             <field name="groups_id" eval="[(5,)]"/>
-            <field name="share" eval="True" />
         </record>
 
         <!-- Add the demo user to the portal (and therefore to the portal member group) -->
diff --git a/addons/portal/wizard/portal_wizard.py b/addons/portal/wizard/portal_wizard.py
index 3973bf6b131..3422a41baff 100644
--- a/addons/portal/wizard/portal_wizard.py
+++ b/addons/portal/wizard/portal_wizard.py
@@ -209,7 +209,6 @@ class wizard_user(osv.osv_memory):
             'login': extract_email(wizard_user.email),
             'partner_id': wizard_user.partner_id.id,
             'groups_id': [(6, 0, [])],
-            'share': True,
         }
         user_id = res_users.create(cr, uid, values, context=create_context)
         return res_users.browse(cr, uid, user_id, context)
diff --git a/addons/share/res_users.py b/addons/share/res_users.py
index 30200133f8e..702522478dd 100644
--- a/addons/share/res_users.py
+++ b/addons/share/res_users.py
@@ -38,9 +38,25 @@ class res_groups(osv.osv):
 class res_users(osv.osv):
     _name = 'res.users'
     _inherit = 'res.users'
+
+    def _is_share(self, cr, uid, ids, name, args, context=None):
+        res = {}
+        for user in self.browse(cr, uid, ids, context=context):
+            res[user.id] = not self.has_group(cr, user.id, 'base.group_user')
+        return res
+
+    def _get_users_from_group(self, cr, uid, ids, context=None):
+        result = set()
+        for group in self.pool['res.groups'].browse(cr, uid, ids, context=context):
+            result.update(user.id for user in group.users)
+        return list(result)
+
     _columns = {
-        'share': fields.boolean('Share User', readonly=True,
-                    help="External user with limited access, created only for the purpose of sharing data.")
+        'share': fields.function(_is_share, string='Share User', type='boolean',
+            store={
+                'res.users': (lambda self, cr, uid, ids, c={}: ids, None, 50),
+                'res.groups': (_get_users_from_group, None, 50),
+            }, help="External user with limited access, created only for the purpose of sharing data."),
      }
 
 # vim:expandtab:smartindent:tabstop=4:softtabstop=4:shiftwidth=4:
diff --git a/addons/share/share_data.xml b/addons/share/share_data.xml
index aba154a6403..c64a9099721 100644
--- a/addons/share/share_data.xml
+++ b/addons/share/share_data.xml
@@ -3,7 +3,6 @@
     <data noupdate="1">
         <record id="base.public_user" model="res.users">
             <field eval="[(4, ref('group_share_user'))]" name="groups_id"/>
-            <field name="share" eval="True" />
         </record>
     </data>
 </openerp>
diff --git a/addons/share/wizard/share_wizard.py b/addons/share/wizard/share_wizard.py
index 10937015dd6..551b08d02cf 100644
--- a/addons/share/wizard/share_wizard.py
+++ b/addons/share/wizard/share_wizard.py
@@ -258,7 +258,6 @@ class share_wizard(osv.TransientModel):
                         'name': new_user,
                         'email': new_user,
                         'groups_id': [(6,0,[group_id])],
-                        'share': True,
                         'company_id': current_user.company_id.id,
                         'company_ids': [(6, 0, [current_user.company_id.id])],
                 }, context)
@@ -276,7 +275,6 @@ class share_wizard(osv.TransientModel):
                 'password': new_pass,
                 'name': new_login,
                 'groups_id': [(6,0,[group_id])],
-                'share': True,
                 'company_id': current_user.company_id.id,
                 'company_ids': [(6, 0, [current_user.company_id.id])],
             }, context)