diff --git a/addons/purchase/purchase.py b/addons/purchase/purchase.py
index eea61a7b3c9..accce18ddbb 100644
--- a/addons/purchase/purchase.py
+++ b/addons/purchase/purchase.py
@@ -1007,10 +1007,12 @@ class purchase_order_line(osv.osv):
             context_partner.update( {'lang': lang, 'partner_id': partner_id} )
         product = product_product.browse(cr, uid, product_id, context=context_partner)
         #call name_get() with partner in the context to eventually match name and description in the seller_ids field
-        dummy, name = product_product.name_get(cr, uid, product_id, context=context_partner)[0]
-        if product.description_purchase:
-            name += '\n' + product.description_purchase
-        res['value'].update({'name': name})
+        if not name or not uom_id:
+            # The 'or not uom_id' part of the above condition can be removed in master. See commit message of the rev. introducing this line.
+            dummy, name = product_product.name_get(cr, uid, product_id, context=context_partner)[0]
+            if product.description_purchase:
+                name += '\n' + product.description_purchase
+            res['value'].update({'name': name})
 
         # - set a domain on product_uom
         res['domain'] = {'product_uom': [('category_id','=',product.uom_id.category_id.id)]}
diff --git a/addons/purchase/purchase_view.xml b/addons/purchase/purchase_view.xml
index 3c8afceb6e7..41088f998a9 100644
--- a/addons/purchase/purchase_view.xml
+++ b/addons/purchase/purchase_view.xml
@@ -205,7 +205,7 @@
                         <page string="Purchase Order">
                             <field name="order_line">
                                 <tree string="Purchase Order Lines" editable="bottom">
-                                    <field name="product_id" on_change="onchange_product_id(parent.pricelist_id,product_id,0,False,parent.partner_id, parent.date_order,parent.fiscal_position,date_planned,name,price_unit,context)"/>
+                                    <field name="product_id" on_change="onchange_product_id(parent.pricelist_id,product_id,0,False,parent.partner_id, parent.date_order,parent.fiscal_position,date_planned,False,price_unit,context)"/>
                                     <field name="name"/>
                                     <field name="date_planned"/>
                                     <field name="company_id" groups="base.group_multi_company" widget="selection"/>