src/jdk/nashorn/api/scripting/ScriptObjectMirror.java

@@ -500,11 +500,11 @@
      * @param proto new proto for this object
      */
     public void setProto(final Object proto) {
         inGlobal(new Callable<Void>() {
             @Override public Void call() {
-                sobj.setProtoCheck(unwrap(proto, global));
+                sobj.setPrototypeOf(unwrap(proto, global));
                 return null;
             }
         });
     }