diff --git a/xml/impl/src/com/intellij/lang/xml/XMLExternalAnnotator.java b/xml/impl/src/com/intellij/lang/xml/XMLExternalAnnotator.java
index c9a8d6583bc0..905e06b8c115 100644
--- a/xml/impl/src/com/intellij/lang/xml/XMLExternalAnnotator.java
+++ b/xml/impl/src/com/intellij/lang/xml/XMLExternalAnnotator.java
@@ -45,6 +45,8 @@ public class XMLExternalAnnotator implements ExternalAnnotator, Validator.Valida
     XmlNSDescriptor nsDescriptor = rootTag == null ? null : rootTag.getNSDescriptor(rootTag.getNamespace(), false);
 
     if (nsDescriptor instanceof Validator && !HtmlUtil.isHtml5Document(document)) {
+      XmlFile descriptorFile = nsDescriptor.getDescriptorFile();
+      if (descriptorFile != null && !descriptorFile.isPhysical()) return;
       ((Validator<XmlDocument>)nsDescriptor).validate(document, this);
     }
   }