diff -r dde8422fb5ae -r 5e8f219d60ba vm/src/main/java/org/apidesign/vm4brwsr/ByteCodeToJavaScript.java
--- a/vm/src/main/java/org/apidesign/vm4brwsr/ByteCodeToJavaScript.java	Sat Dec 01 15:48:12 2012 +0100
+++ b/vm/src/main/java/org/apidesign/vm4brwsr/ByteCodeToJavaScript.java	Sun Dec 02 06:26:32 2012 +0100
@@ -174,7 +174,7 @@
             out.append("  var s = new Array();\n");
             produceCode(code);
         } else {
-            out.append("  /* no code found for ").append(m.getInternalSig()).append(" */\n");
+            out.append("  throw 'no code found for ").append(m.getInternalSig()).append("';\n");
         }
         out.append("};");
     }
@@ -208,7 +208,7 @@
             out.append(";\n  var s = new Array();\n");
             produceCode(code);
         } else {
-            out.append("  /* no code found for ").append(m.getInternalSig()).append(" */\n");
+            out.append("  throw 'no code found for ").append(m.getInternalSig()).append("';\n");
         }
         out.append("};");
     }