diff -r d382dacfd73f -r 3d1612be40bc rt/vm/src/test/java/org/apidesign/vm4brwsr/ByteCodeToJavaScriptTest.java
--- a/rt/vm/src/test/java/org/apidesign/vm4brwsr/ByteCodeToJavaScriptTest.java	Tue Feb 26 16:54:16 2013 +0100
+++ b/rt/vm/src/test/java/org/apidesign/vm4brwsr/ByteCodeToJavaScriptTest.java	Thu Nov 07 09:41:45 2013 +0100
@@ -52,4 +52,15 @@
         assertTrue(returnType[0] != 'V', "Returns string");
         assertEquals(ret, "toJavaScript__Ljava_lang_String_2_3B");
     }
+    
+    @Test public void mangleJsCallbackToAType() throws Exception {
+        String res = ByteCodeToJavaScript.mangleJsCallbacks(
+            "org.apidesign.bck2brwsr.vmtest.impl.HtmlAnnotations",
+            "onError", "Ljava/lang/Object;", false
+        );
+        assertEquals(res, 
+            "org_1apidesign_1bck2brwsr_1vmtest_1impl_1HtmlAnnotations$onError$Ljava_1lang_1Object_12__Ljava_lang_Object_2Lorg_apidesign_bck2brwsr_vmtest_impl_HtmlAnnotations_2Ljava_lang_Object_2",
+            "Pretty long method name"
+        );
+    }
 }