diff -r 6506d5132e03 -r 7c4442271367 emul/src/main/java/java/lang/Object.java
--- a/emul/src/main/java/java/lang/Object.java	Mon Jan 07 16:46:09 2013 +0100
+++ b/emul/src/main/java/java/lang/Object.java	Sat Jan 12 15:39:33 2013 +0100
@@ -106,11 +106,14 @@
      */
     @JavaScriptBody(args = "self", body = 
         "if (self.$hashCode) return self.$hashCode;\n"
-        + "var h = Math.random() * Math.pow(2, 32);\n"
+        + "var h = self.computeHashCode__I(self);\n"
         + "return self.$hashCode = h & h;"
     )
     public native int hashCode();
 
+    @JavaScriptBody(args = "self", body = "Math.random() * Math.pow(2, 32);")
+    native int computeHashCode();
+    
     /**
      * Indicates whether some other object is "equal to" this one.
      * <p>