diff --git a/addons/sale_stock/i18n/sale_stock.pot b/addons/sale_stock/i18n/sale_stock.pot
index 36dba4e9e59..93d44e66e2a 100644
--- a/addons/sale_stock/i18n/sale_stock.pot
+++ b/addons/sale_stock/i18n/sale_stock.pot
@@ -142,7 +142,7 @@ msgstr ""
 #. module: sale_stock
 #: code:addons/sale_stock/sale_stock.py:148
 #, python-format
-msgid "Ordered quantity changed!"
+msgid "Ordered quantity decreased!"
 msgstr ""
 
 #. module: sale_stock
@@ -262,7 +262,7 @@ msgstr ""
 #. module: sale_stock
 #: code:addons/sale_stock/sale_stock.py:149
 #, python-format
-msgid "You have changed the quantity ordered! If the quantity was decreased, you need to modify manually the delivery order."
+msgid "You are decreasing the ordered quantity! Do not forget to manually update the delivery order if needed."
 msgstr ""
 
 #. module: sale_stock
diff --git a/addons/sale_stock/sale_stock.py b/addons/sale_stock/sale_stock.py
index 049857267ff..59b9f24dfce 100644
--- a/addons/sale_stock/sale_stock.py
+++ b/addons/sale_stock/sale_stock.py
@@ -148,10 +148,10 @@ class SaleOrderLine(models.Model):
 
     @api.onchange('product_uom_qty')
     def _onchange_product_uom_qty(self):
-        if self.state == 'sale' and self.product_id.type != 'service':
+        if self.state == 'sale' and self.product_id.type != 'service' and self.product_uom_qty < self._origin.product_uom_qty:
             warning_mess = {
-                'title': _('Ordered quantity changed!'),
-                'message' : _('You are changing the ordered quantity! If you decreased the initial quantity, do not forget to manually update the delivery order if needed.'),
+                'title': _('Ordered quantity decreased!'),
+                'message' : _('You are decreasing the ordered quantity! Do not forget to manually update the delivery order if needed.'),
             }
             return {'warning': warning_mess}
         return {}