Index: C:/harmony/trunk_0427/modules/luni/src/main/java/java/io/ObjectOutputStream.java =================================================================== --- C:/harmony/trunk_0427/modules/luni/src/main/java/java/io/ObjectOutputStream.java (revision 421079) +++ C:/harmony/trunk_0427/modules/luni/src/main/java/java/io/ObjectOutputStream.java (working copy) @@ -1750,6 +1750,10 @@ private void writeObject(Object object, boolean unshared) throws IOException { + if (object != null && !ObjectStreamClass.isSerializable(object.getClass())) { + throw new NotSerializableException(object.getClass().getName()); + } boolean setOutput = (primitiveTypes == output); if (setOutput) { primitiveTypes = null;