diff -r e3f671b50e93 -r 4fe8b3dfc55f vm/src/test/java/org/apidesign/vm4brwsr/TestUtils.java
--- a/vm/src/test/java/org/apidesign/vm4brwsr/TestUtils.java	Wed Jan 30 22:23:21 2013 +0100
+++ b/vm/src/test/java/org/apidesign/vm4brwsr/TestUtils.java	Fri Feb 08 11:12:02 2013 +0100
@@ -40,7 +40,7 @@
         if (ret == null && expRes == null) {
             return null;
         }
-        if (expRes.equals(ret)) {
+        if (expRes != null && expRes.equals(ret)) {
             return null;
         }
         if (expRes instanceof Number) {