Architecture-Driven Modernization is the new generation of software reengineering. The main idea is to modernize legacy systems using a set of standard models. The first step is to obtain, by reverse engineering, an instance of an ISO metamodel called KDM that represents all details of the legacy system. Then, refactorings and optimizations can be applied over this model turning it into a target/modernized KDM. Afterwards the source code of the target system can be generated. In its original form, KDM does not provide aspectual concepts, preventing an aspect-oriented modernization to be properly conducted. In this paper we present KDM-AO, an aspect-oriented heavyweight extension for the KDM metamodel. The extension has been created based on a well known aspectoriented profile for AspectJ language. To evaluate our extension, we applied it in an aspect-oriented modernization whose goal was to remodularize the persistence concern of an application using a Persistence Crosscutting Framework. The case study showed that KDM-AO is able to represent high-level and low-level aspectoriented abstractions.