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 166bbaba3c5b..eb71a4d6cec5 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
@@ -787,7 +787,7 @@ public abstract class DomInvocationHandler<T extends AbstractDomChildDescription
           @Override
           public DomElement fun(DomStub stub) {
             if (stub instanceof ElementStub && ((ElementStub)stub).isCustom()) {
-              EvaluatedXmlName name = new DummyEvaluatedXmlName(stub.getName(), null);
+              EvaluatedXmlName name = new DummyEvaluatedXmlName(stub.getName(), "");
               return new CollectionElementInvocationHandler(name, (CustomDomChildrenDescriptionImpl)description, myManager, (ElementStub)stub).getProxy();
             }
             return null;
diff --git a/xml/dom-openapi/src/com/intellij/util/xml/DummyEvaluatedXmlName.java b/xml/dom-openapi/src/com/intellij/util/xml/DummyEvaluatedXmlName.java
index a42968321cdd..30dbe7f18bd1 100644
--- a/xml/dom-openapi/src/com/intellij/util/xml/DummyEvaluatedXmlName.java
+++ b/xml/dom-openapi/src/com/intellij/util/xml/DummyEvaluatedXmlName.java
@@ -27,11 +27,11 @@ public class DummyEvaluatedXmlName implements EvaluatedXmlName {
   private final XmlName myXmlName;
   private final String myNamespace;
 
-  public DummyEvaluatedXmlName(final String localName, final String namespace) {
+  public DummyEvaluatedXmlName(final String localName, @NotNull final String namespace) {
     this(new XmlName(localName), namespace);
   }
 
-  public DummyEvaluatedXmlName(final XmlName xmlName, final String namespace) {
+  public DummyEvaluatedXmlName(final XmlName xmlName, @NotNull final String namespace) {
     myXmlName = xmlName;
     myNamespace = namespace;
   }