This call fails, because mockito tries to modify the passed in list:

ReflectUtils.addAllInterfaces( MyClass.class, Arrays.asList(new Object[] { Serializable.class }) );

Please clone the list, as it will also allow multiple sequential calls, which are currently not possible. Ex: ReflectUtils.addAllInterfaces(One.class, myNewInterfaces); ReflectUtils.addAllInterfaces(Two.class, myNewInterfaces);

Tested with Mockito 1.9.0

This class is part of the repackaged cglib & asm. I'm not sure we want to modify this code however the modification is easy, as we might update this code in the future without repatching this or other files. Especially since there is new activity in the project, let's cross fingers!

Anyway just use the copy constructor of an Arraylist, plus it has the benefit that you provide the list implementation!

Cheers Brice