diff --git a/addons/project_issue/project_issue.py b/addons/project_issue/project_issue.py
index 2a02309e2fa..aaaff37305e 100644
--- a/addons/project_issue/project_issue.py
+++ b/addons/project_issue/project_issue.py
@@ -208,7 +208,7 @@ class project_issue(crm.crm_case, osv.osv):
                                 method=True, multi='day_open', type="float", store=True),
         'day_close': fields.function(_compute_day, string='Days to Close', \
                                 method=True, multi='day_close', type="float", store=True),
-        'assigned_to': fields.related('task_id', 'user_id', string = 'Assigned to', type="many2one", relation="res.users", store=True, readonly=True, help='This is the current user to whom the related task have been assigned'),
+        'assigned_to': fields.related('task_id', 'user_id', string = 'Assigned to', type="many2one", relation="res.users", store=True, help='This is the current user to whom the related task have been assigned'),
         'working_hours_open': fields.function(_compute_day, string='Working Hours to Open the Issue', \
                                 method=True, multi='working_days_open', type="float", store=True),
         'working_hours_close': fields.function(_compute_day, string='Working Hours to Close the Issue', \
diff --git a/addons/project_issue/project_issue_view.xml b/addons/project_issue/project_issue_view.xml
index 23a361b0ff9..36c0e4ba82f 100644
--- a/addons/project_issue/project_issue_view.xml
+++ b/addons/project_issue/project_issue_view.xml
@@ -189,7 +189,7 @@
                     <button name="next_type" string="Next" type="object" icon="gtk-go-forward" help="Change to Next Stage"/>
                     <field name="version_id" widget="selection"/>
                     <field name="user_id"/>
-                    <field name="assigned_to"/>
+                    <field name="assigned_to" attrs="{'readonly':[('task_id','=',False)]}"/>
                     <field name="progress" widget="progressbar" attrs="{'invisible':[('task_id','=',False)]}"/>
                     <field name="state"/>
                     <button name="case_cancel" string="Cancel" states="draft,open,pending" type="object" icon="gtk-cancel"/>