Install Linux Kernel Headers?

Hi,

I'm trying to build btier on my AlpineLinux install. Since btier is a kernel module it needs access to the kernel headers. They don't appear to be installed by default, and the only package I can find is "linux-headers-4.1.12-r0" which don't match me kernel version and don't appear to include the full kernel headers. How would I go about getting these files so I can compile against them?