diff --git a/nbxml/src/main/java/org/apache/vysper/xml/fragment/Renderer.java b/nbxml/src/main/java/org/apache/vysper/xml/fragment/Renderer.java
index ac2057e..21cc8c5 100644
--- a/nbxml/src/main/java/org/apache/vysper/xml/fragment/Renderer.java
+++ b/nbxml/src/main/java/org/apache/vysper/xml/fragment/Renderer.java
@@ -136,7 +136,7 @@
 
     private void renderAttribute(StringBuilder buffer, Attribute attribute, ResolverNamespaceResolver nsResolver) {
         String qname;
-        if (!attribute.getNamespaceUri().equals("")) {
+        if (!attribute.getNamespaceUri().isEmpty()) {
             // attribute is in a namespace, resolve prefix
             qname = nsResolver.resolvePrefix(attribute.getNamespaceUri()) + ":" + attribute.getName();
         } else {