diff -r af9c8df8a660 -r c12342170235 vm/src/test/java/org/apidesign/vm4brwsr/VMinVMTest.java
--- a/vm/src/test/java/org/apidesign/vm4brwsr/VMinVMTest.java	Tue Dec 11 10:24:00 2012 +0100
+++ b/vm/src/test/java/org/apidesign/vm4brwsr/VMinVMTest.java	Tue Dec 11 11:05:06 2012 +0100
@@ -38,6 +38,10 @@
     @Test public void compareGeneratedCodeForArrayClass() throws Exception {
         compareCode("/org/apidesign/vm4brwsr/Array.class");
     }
+
+    @Test public void compareGeneratedCodeForClassesClass() throws Exception {
+        compareCode("/org/apidesign/vm4brwsr/Classes.class");
+    }
     
     @BeforeClass
     public void compileTheCode() throws Exception {
@@ -91,9 +95,12 @@
         assertTrue(ret instanceof String, "It is string: " + ret);
         
         if (!ret1.toString().equals(ret)) {
-            StringBuilder msg = StaticMethodTest.dumpJS(ret1);
-            msg.append(" is not the same as ");
+            StringBuilder msg = new StringBuilder("Difference found between ");
+            msg.append(StaticMethodTest.dumpJS(ret1));
+            msg.append(" ");
             msg.append(StaticMethodTest.dumpJS((CharSequence) ret));
+            msg.append(" compiled by ");
+            msg.append(StaticMethodTest.dumpJS(codeSeq));
             fail(msg.toString());
         }
     }