diff --git a/golem_activity_registration_payment/__manifest__.py b/golem_activity_registration_payment/__manifest__.py
index 87325cc..99193bf 100644
--- a/golem_activity_registration_payment/__manifest__.py
+++ b/golem_activity_registration_payment/__manifest__.py
@@ -1,6 +1,7 @@
 # -*- coding: utf-8 -*-
 
 #    Copyright 2018 Fabien Bourgeois <fabien@yaltik.com>
+#    Copyright 2018 Youssef El Ouahby <youssef@yaltik.com>
 #
 #    This program is free software: you can redistribute it and/or modify
 #    it under the terms of the GNU Affero General Public License as
@@ -19,7 +20,7 @@
     'name': 'GOLEM Activity Member Registration Payments',
     'summary': 'GOLEM Activities Member Registration Payments',
     'description': 'GOLEM Activities Member Registration Payments',
-    'version': '10.0.0.3.6',
+    'version': '10.0.0.4.0',
     'category': 'GOLEM',
     'author': 'Fabien Bourgeois',
     'license': 'AGPL-3',
diff --git a/golem_activity_registration_payment/models/golem_activity.py b/golem_activity_registration_payment/models/golem_activity.py
index 71acdb6..9dcd94b 100644
--- a/golem_activity_registration_payment/models/golem_activity.py
+++ b/golem_activity_registration_payment/models/golem_activity.py
@@ -18,10 +18,17 @@
 
 """ GOLEM Activity adaptations """
 
-from odoo import models, fields
+from odoo import models, fields, api
 
 class GolemActivity(models.Model):
     """ GOLEM Activity adaptations """
     _inherit = 'golem.activity'
 
-    free_activity = fields.Boolean(required=True)
+    free_activity = fields.Boolean(default=False)
+
+    @api.onchange('free_activity')
+    def onchange_free_activity(self):
+        """ If free activity, price should be 0.0 """
+        for activity in self:
+            if activity.free_activity:
+                activity.list_price = 0.0
diff --git a/golem_activity_registration_payment/models/golem_activity_registration.py b/golem_activity_registration_payment/models/golem_activity_registration.py
index b3d5361..9e8b475 100644
--- a/golem_activity_registration_payment/models/golem_activity_registration.py
+++ b/golem_activity_registration_payment/models/golem_activity_registration.py
@@ -31,3 +31,4 @@ class GolemActivityRegistration(models.Model):
     invoice_id = fields.Many2one(related='invoice_line_id.invoice_id')
     invoice_state = fields.Selection(related='invoice_line_id.invoice_id.state',
                                      store=True)
+    free_activity = fields.Boolean(related='activity_id.free_activity')
diff --git a/golem_activity_registration_payment/models/golem_member.py b/golem_activity_registration_payment/models/golem_member.py
index b11a777..30aa5b2 100644
--- a/golem_activity_registration_payment/models/golem_member.py
+++ b/golem_activity_registration_payment/models/golem_member.py
@@ -35,9 +35,9 @@ class GolemMember(models.Model):
             regis = member.activity_registration_ids
             regis = regis.filtered(
                 lambda r: (r.state == 'confirmed' and
+                           not r.activity_id.free_activity and
                            (not r.invoice_line_id or
-                            r.invoice_line_id.invoice_id.state == 'cancel') and
-                           not r.activity_id.free_activity)
+                            r.invoice_line_id.invoice_id.state == 'cancel'))
             )
             member.has_invoicable_registrations = bool(len(regis))
 
@@ -53,10 +53,10 @@ class GolemMember(models.Model):
         self.ensure_one()
         member = self[0]
         registrations = member.activity_registration_ids.filtered(
-            lambda r: r.state == 'confirmed' and
-            (not r.invoice_line_id or
-             r.invoice_line_id.invoice_id.state == 'cancel') and
-            not r.activity_id.free_activity
+            lambda r: (r.state == 'confirmed' and
+                       not r.activity_id.free_activity and
+                       (not r.invoice_line_id or
+                        r.invoice_line_id.invoice_id.state == 'cancel'))
         )
         if registrations:
             invoicing = self.env['golem.activity.registration.invoicing'].create({
diff --git a/golem_activity_registration_payment/views/golem_activity_registration_views.xml b/golem_activity_registration_payment/views/golem_activity_registration_views.xml
index 86fb72c..3bae912 100644
--- a/golem_activity_registration_payment/views/golem_activity_registration_views.xml
+++ b/golem_activity_registration_payment/views/golem_activity_registration_views.xml
@@ -45,6 +45,12 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
       <field name="inherit_id"
         ref="golem_activity_registration_state.golem_activity_registration_tree_inherit_state" />
       <field name="arch" type="xml">
+        <field name="activity_price" position="before">
+          <field name="free_activity" readonly="1" />
+        </field>
+        <field name="activity_price" position="attributes">
+          <attribute name="attrs">{'readonly': [('free_activity', '=', True)]}</attribute>
+        </field>
         <field name="state" position="after">
           <field name="invoice_line_id" invisible="1" />
           <field name="invoice_state" string="Invoice state" />
diff --git a/golem_activity_registration_payment/views/golem_activity_views.xml b/golem_activity_registration_payment/views/golem_activity_views.xml
index 1ee833a..08ba1be 100644
--- a/golem_activity_registration_payment/views/golem_activity_views.xml
+++ b/golem_activity_registration_payment/views/golem_activity_views.xml
@@ -22,24 +22,29 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
     <!-- Forms -->
     <record id="golem_activity_form_inherit_activity_registration_payment"
       model="ir.ui.view">
-     <field name="name">Golem activity form activity registration payment adaptations</field>
+     <field name="name">Golem activity form adaptations</field>
      <field name="model">golem.activity</field>
      <field name="inherit_id" ref="golem_activity.golem_activity_form" />
      <field name="arch" type="xml">
-      <field name="list_price" position="after">
-        <field name='free_activity'/>
+      <field name="list_price" position="attributes">
+        <attribute name="attrs">{'invisible': [('free_activity', '=', True)]}</attribute>
+      </field>
+      <field name="list_price" position="before">
+        <field name='free_activity' />
       </field>
      </field>
    </record>
+
    <!-- Search -->
    <record id="golem_activity_search_inherit_activity_registration_payment"
   model="ir.ui.view">
-     <field name="name">Golem Activity Search activity registration payment adaptations</field>
+     <field name="name">Golem Activity Search adaptations</field>
      <field name="model">golem.activity</field>
      <field name="inherit_id" ref="golem_activity.golem_activity_search" />
      <field name="arch" type="xml">
        <filter name="season_default" position="after">
-         <filter name="free_activity" string="Free activity" domain="[('free_activity', '=', True)]"/>
+         <filter name="free_activity" string="Free activity"
+           domain="[('free_activity', '=', True)]" />
        </filter>
      </field>
     </record>