diff --git a/models/calendar.py b/models/calendar.py
index 7c827da1db48611dbb65cef122db1eff470de94a..7d9cd8739482d72a5464fdfe0147fd7aadf51be5 100644
--- a/models/calendar.py
+++ b/models/calendar.py
@@ -53,6 +53,13 @@ class CGScopCalendar(models.Model):
     # ------------------------------------------------------
     # onchange
     # ------------------------------------------------------
+    @api.onchange('project_id')
+    def _onchange_project_id(self):
+        if self.project_id.partner_id:
+            self.coop_id = self.project_id.partner_id
+        else:
+            self.coop_id = False
+     
     @api.onchange('coop_id')
     def _onchange_coop_id(self):
         address = ''