diff -r 70e7710a65dc -r f2352e0b713e vm/src/main/java/org/apidesign/vm4brwsr/Main.java
--- a/vm/src/main/java/org/apidesign/vm4brwsr/Main.java	Fri Nov 16 07:36:32 2012 +0100
+++ b/vm/src/main/java/org/apidesign/vm4brwsr/Main.java	Fri Dec 07 15:02:35 2012 +0100
@@ -39,7 +39,10 @@
         Writer w = new BufferedWriter(new FileWriter(args[0]));
         StringArray classes = StringArray.asList(args);
         classes.delete(0);
-        GenJS.compile(w, classes);
-        w.close();
+        try {
+            GenJS.compile(w, classes);
+        } finally {
+            w.close();
+        }
     }
 }