diff --git a/xml/dom-impl/src/com/intellij/util/xml/impl/PhysicalDomParentStrategy.java b/xml/dom-impl/src/com/intellij/util/xml/impl/PhysicalDomParentStrategy.java
index 65d13fdb34d5..546ed073f57c 100644
--- a/xml/dom-impl/src/com/intellij/util/xml/impl/PhysicalDomParentStrategy.java
+++ b/xml/dom-impl/src/com/intellij/util/xml/impl/PhysicalDomParentStrategy.java
@@ -84,7 +84,8 @@ public class PhysicalDomParentStrategy implements DomParentStrategy {
       if (myElement != thatElement) {
         final PsiElement nav1 = myElement.getNavigationElement();
         final PsiElement nav2 = thatElement.getNavigationElement();
-        assert nav1 == nav2 : nav1.getContainingFile() + ":" + nav1.getTextRange().getStartOffset() + "!=" + nav2.getContainingFile() + ":" + nav2.getTextRange().getStartOffset();
+        assert nav1 == nav2 : nav1.getContainingFile() + ":" + nav1.getTextRange().getStartOffset() + "!=" + nav2.getContainingFile() + ":" + nav2.getTextRange().getStartOffset() +
+                              "; " + (nav1==myElement) + ";" + (nav2==thatElement);
       }
       return true;
     }