diff --git a/jackrabbit-webdav/src/main/java/org/apache/jackrabbit/webdav/xml/Namespace.java b/jackrabbit-webdav/src/main/java/org/apache/jackrabbit/webdav/xml/Namespace.java
index 2aa8515..fc02913 100644
--- a/jackrabbit-webdav/src/main/java/org/apache/jackrabbit/webdav/xml/Namespace.java
+++ b/jackrabbit-webdav/src/main/java/org/apache/jackrabbit/webdav/xml/Namespace.java
@@ -65,6 +65,9 @@ public class Namespace {
     }
 
     public boolean isSame(String namespaceURI) {
+        if (namespaceURI == null && uri == "") {
+            return true;
+        }
         return uri.equals(namespaceURI);
     }