I don't think that it makes any sense even to talk about the class loader that was used to create a ParameterizedType.  Clearly there was a class loader used to resolve the class names that are passed when a ParameterizedType is created, but I don't think the information is recorded anywhere. The core bug here seems to be that cacheing is being done inappropriately. Can you write a test case, please?  One that demonstrates the bug in   //Fails - loader is loaderA   assertEquals(loaderB, infoB.getActualTypeArguments[0].getClassLoader()); It has to be complete and runnable as a standalone program.