diff --git a/product/ERP5Type/Core/AttributeEqualityConstraint.py b/product/ERP5Type/Core/AttributeEqualityConstraint.py
index ad5fb132482ea115363490489a0be850450c8350..d79b5bcbd5b0daf53e705c98e3393c4e7b6e678e 100644
--- a/product/ERP5Type/Core/AttributeEqualityConstraint.py
+++ b/product/ERP5Type/Core/AttributeEqualityConstraint.py
@@ -74,7 +74,8 @@ class AttributeEqualityConstraint(PropertyExistenceConstraint):
 
     error = self._checkPropertyConsistency(obj, attribute_name)
     if error:
-      return [error]
+      return [self._generateError(obj, self._getMessage(error),
+        dict(property_id=attribute_name))]
 
     identical = True