diff --git a/addons/product/product.py b/addons/product/product.py
index 035ff1f0faa..0672f6f392d 100644
--- a/addons/product/product.py
+++ b/addons/product/product.py
@@ -69,7 +69,7 @@ class product_uom(osv.osv):
         'name': fields.char('Name', size=64, required=True, translate=True),
         'category_id': fields.many2one('product.uom.categ', 'UoM Category', required=True, ondelete='cascade',
             help="Quantity conversions may happen automatically between Units of Measure in the same category, according to their respective ratios."),
-        'factor': fields.float('Ratio', digits_compute=dp.get_precision('Product UoM'), required=True,
+        'factor': fields.float('Ratio', required=True,digits=(12, 6),
             help='How many times this UoM is smaller than the reference UoM in this category:\n'\
                     '1 * (reference unit) = ratio * (this unit)'),
         'factor_inv': fields.function(_factor_inv, digits_compute=dp.get_precision('Product UoM'),