diff --git a/tests/test_product.py b/tests/test_product.py
index 748f853515..88c7c520fa 100644
--- a/tests/test_product.py
+++ b/tests/test_product.py
@@ -66,17 +66,17 @@ class ProductTestCase(unittest.TestCase):
                 })
             transaction.cursor.commit()
 
-            self.failUnlessRaises(Exception, self.uom.write, {
+            self.failUnlessRaises(Exception, self.uom.write, category_id, {
                 'rate': 0.0,
                 })
             transaction.cursor.rollback()
 
-            self.failUnlessRaises(Exception, self.uom.write, {
+            self.failUnlessRaises(Exception, self.uom.write, category_id, {
                 'factor': 0.0,
                 })
             transaction.cursor.rollback()
 
-            self.failUnlessRaises(Exception, self.uom.write, {
+            self.failUnlessRaises(Exception, self.uom.write, category_id, {
                 'rate': 0.0,
                 'factor': 0.0,
                 })