Namespace and cap-add

Hey, is it possible to use docker user namespace and cap-add such as --cap-add=IPC_LOCK?

This seems to be failing for me as when I docker run an app with --cap-add=IPC_LOCK and with userns-remap the docker app is not able to use malloc, while if I run the same app still with --cap-add=IPC_LOCK, but without userns-remap it works properly.

Any ideas?