High-level synthesis (HLS) tools have made significant progress in the past few years, improving the design productivity for hardware accelerators and becoming mainstream in industry to create specialized system-on-chip architectures. Increasing the level of security of these heterogeneous architectures is becoming critical. However, state-of-the-art security countermeasures are still applied only to the code executing on the processor cores or manually implemented into the generated components, leading to suboptimal and sometimes even insecure designs. This letter discusses extensions to HLS tools for creating secure heterogeneous architectures