libx264 build error Ubuntu 16.04

[coreybruce]

libavcodec/libx264.c: In function ‘X264_frame’:
libavcodec/libx264.c:282:9: error: ‘x264_bit_depth’ undeclared (first use in this function)
     if (x264_bit_depth > 8)
         ^
libavcodec/libx264.c:282:9: note: each undeclared identifier is reported only once for each function it appears in
libavcodec/libx264.c: In function ‘X264_init_static’:
libavcodec/libx264.c:892:9: error: ‘x264_bit_depth’ undeclared (first use in this function)
     if (x264_bit_depth == 8)
         ^
common.mak:60: recipe for target 'libavcodec/libx264.o' failed
make: *** [libavcodec/libx264.o] Error 1
make: *** Waiting for unfinished jobs....