virtualbox-guest-additions fail to build for kernel 4.14.x

reason:

kernel 4.14 requires at minimum virtualbox version 5.1.31 (NOT 5.1.30)

from my experience version 5.1.31 works on all distros (slackware, devuan, CRUX) with all kernels tested: f4om 4.9.x to 4.14.3

while virtualbox 5.2.x has problems with linux, 5.1.31 works with host as well as with guest VM

Is it possible to update funtoo's virtualbox to 5.1.31?

Thank you