diff --git a/addons/stock/stock.py b/addons/stock/stock.py
index 7fa2f4e92a2..e8cdbca3105 100644
--- a/addons/stock/stock.py
+++ b/addons/stock/stock.py
@@ -2328,7 +2328,7 @@ class stock_move(osv.osv):
         if move.location_dest_id.usage != 'internal' and move.product_id.cost_method == 'average':
             reference_amount = qty * move.product_id.standard_price
         elif move.product_id.cost_method == 'average' and move.price_unit:
-            reference_amount = qty * move.price_unit
+            reference_amount = move.product_qty * move.price_unit
             reference_currency_id = move.price_currency_id.id or reference_currency_id
 
         # Otherwise we default to the company's valuation price type, considering that the values of the