diff --git a/project_milestone/__manifest__.py b/project_milestone/__manifest__.py
index 308f8ace61..9b2707c147 100644
--- a/project_milestone/__manifest__.py
+++ b/project_milestone/__manifest__.py
@@ -8,7 +8,7 @@
     'category': 'Project Management',
     'version': '12.0.1.0.0',
     'license': 'AGPL-3',
-    'depends': ['project', 'project_stage_closed'],
+    'depends': ['mail', 'project', 'project_stage_closed'],
     'data': [
         'views/project.xml',
         'views/project_task.xml',
diff --git a/project_milestone/models/project_milestone.py b/project_milestone/models/project_milestone.py
index d2db1f1690..865f6b2cae 100644
--- a/project_milestone/models/project_milestone.py
+++ b/project_milestone/models/project_milestone.py
@@ -5,6 +5,7 @@
 
 class ProjectMilestone(models.Model):
     _name = 'project.milestone'
+    _inherit = ['mail.thread', 'mail.activity.mixin']
     _order = 'project_id,sequence'
     _description = 'Project Milestone'
 
diff --git a/project_milestone/views/project_milestone.xml b/project_milestone/views/project_milestone.xml
index 6f9e2f1a95..f1aa036f9d 100644
--- a/project_milestone/views/project_milestone.xml
+++ b/project_milestone/views/project_milestone.xml
@@ -50,6 +50,11 @@
                         <field name="fold"/>
                     </group>
                 </sheet>
+                <div class="oe_chatter">
+                    <field name="message_follower_ids" widget="mail_followers" />
+                    <field name="activity_ids" />
+                    <field name="message_ids" widget="mail_thread" />
+                </div>
             </form>
         </field>
     </record>