diff --git a/xml/dom-impl/src/com/intellij/util/xml/impl/DomInvocationHandler.java b/xml/dom-impl/src/com/intellij/util/xml/impl/DomInvocationHandler.java
index ffed7dd25819..2e6e3394de68 100644
--- a/xml/dom-impl/src/com/intellij/util/xml/impl/DomInvocationHandler.java
+++ b/xml/dom-impl/src/com/intellij/util/xml/impl/DomInvocationHandler.java
@@ -584,6 +584,7 @@ public abstract class DomInvocationHandler<T extends AbstractDomChildDescription
       final XmlAttribute attribute = tag.getAttribute(description.getXmlName().getLocalName(), ns.equals(tag.getNamespace())? null:ns);
       
       if (attribute != null) {
+        LOG.assertTrue(attribute.isValid());
         return myManager.getSemService().getSemElement(DomManagerImpl.DOM_ATTRIBUTE_HANDLER_KEY, attribute);
       }
     }