diff --git a/addons/product/product.py b/addons/product/product.py
index a81074aa56e..3cbff880cf9 100644
--- a/addons/product/product.py
+++ b/addons/product/product.py
@@ -559,8 +559,8 @@ class product_product(osv.osv):
         return False
 
     def _check_ean_key(self, cr, uid, ids, context=None):
-        for product in self.browse(cr, uid, ids, context=context):
-            res = check_ean(product.ean13)
+        for product in self.read(cr, uid, ids, ['ean13'], context=context):
+            res = check_ean(product['ean13'])
         return res
 
     _constraints = [(_check_ean_key, 'Error: Invalid ean code', ['ean13'])]
diff --git a/addons/stock/product.py b/addons/stock/product.py
index 62fdbb24ca2..e4164ef9e1f 100644
--- a/addons/stock/product.py
+++ b/addons/stock/product.py
@@ -243,13 +243,16 @@ class product_product(osv.osv):
             child_location_ids = location_obj.search(cr, uid, [('location_id', 'child_of', location_ids)])
             location_ids = child_location_ids or location_ids
         
-        # this will be a dictionary of the UoM resources we need for conversion purposes, by UoM id
-        uoms_o = {}
         # this will be a dictionary of the product UoM by product id
         product2uom = {}
-        for product in self.browse(cr, uid, ids, context=context):
-            product2uom[product.id] = product.uom_id.id
-            uoms_o[product.uom_id.id] = product.uom_id
+        uom_ids = []
+        for product in self.read(cr, uid, ids, ['uom_id'], context=context):
+            product2uom[product['id']] = product['uom_id'][0]
+            uom_ids.append(product['uom_id'][0])
+        # this will be a dictionary of the UoM resources we need for conversion purposes, by UoM id
+        uoms_o = {}
+        for uom in self.pool.get('product.uom').browse(cr, uid, uom_ids, context=context):
+            uoms_o[uom.id] = uom
 
         results = []
         results2 = []