Updating a native class pointer in persisted compiled code for use in an execution environment other than the one in which the native class pointer was created. This is done by using an identifier, stored with the persisted compiled code, of the class first loaded by the class loader that also loaded the class to which the native class pointer refers. A table is maintained in the execution environment mapping class identifiers to class loaders, and the stored identifier is used to consult this table to find a candidate class loader from those in the current execution environment that can provide the correct updated pointer.