diff --git a/addons/hr_timesheet_invoice/hr_timesheet_invoice.py b/addons/hr_timesheet_invoice/hr_timesheet_invoice.py
index 6393e4025c7..f67c129f863 100644
--- a/addons/hr_timesheet_invoice/hr_timesheet_invoice.py
+++ b/addons/hr_timesheet_invoice/hr_timesheet_invoice.py
@@ -77,10 +77,11 @@ class account_analytic_account(osv.osv):
 
     def on_change_partner_id(self, cr, uid, ids, partner_id, name, context=None):
         res = super(account_analytic_account, self).on_change_partner_id(cr, uid, ids, partner_id, name, context=context)
-        part = self.pool.get('res.partner').browse(cr, uid, partner_id, context=context)
-        pricelist = part.property_product_pricelist and part.property_product_pricelist.id or False
-        if pricelist:
-            res['value']['pricelist_id'] = pricelist
+        if partner_id:
+            part = self.pool.get('res.partner').browse(cr, uid, partner_id, context=context)
+            pricelist = part.property_product_pricelist and part.property_product_pricelist.id or False
+            if pricelist:
+                res['value']['pricelist_id'] = pricelist
         return res
 
     def set_close(self, cr, uid, ids, context=None):