diff --git a/addons/project_long_term/project_long_term.py b/addons/project_long_term/project_long_term.py
index ad972b89dad..f13752f86e4 100644
--- a/addons/project_long_term/project_long_term.py
+++ b/addons/project_long_term/project_long_term.py
@@ -144,13 +144,6 @@ class project_phase(osv.osv):
             result['date_start'] = project_id.date_start
         return {'value': result}
 
-    def onchange_days(self, cr, uid, ids, project, context=None):
-        result = {}
-        for id in ids:
-            project_id = self.browse(cr, uid, id, context=context)
-            newdate = datetime.strptime(project_id.date_start, '%Y-%m-%d') + relativedelta(days=project_id.duration or 0.0)
-            result['date_end'] = newdate.strftime('%Y-%m-%d')
-        return {'value': result}
 
     def _check_date_start(self, cr, uid, phase, date_end, context=None):
        """
diff --git a/addons/project_long_term/project_long_term_view.xml b/addons/project_long_term/project_long_term_view.xml
index 37813f84946..79f5d65811b 100644
--- a/addons/project_long_term/project_long_term_view.xml
+++ b/addons/project_long_term/project_long_term_view.xml
@@ -117,7 +117,7 @@
                         </group>
                         <group colspan="6" col="6">
                             <field name="date_start"/>
-                            <field name="duration"  on_change="onchange_days(project_id)" />
+                            <field name="duration"/>
                             <field name="product_uom" nolabel="1" domain="[('category_id.name', '=', 'Working Time')]"/>
                             <field name="date_end"/>
                         </group>