M4 Program - Building Sendmail

I'm running into an error when I build sendmail:

" ERROR: Can not locate an M4 program"

I'm doing the basic install as per the sendmail install doc. Does this
error make sense to any of you? This is just a clip. I'm getting these all
down the line.

[root@petasus sendmail-8.12.6]# sh Build
Making all in:
/extra/sendmail/sendmail-8.12.6/libsm
Configuration: pfx=, os=Linux, rel=2.4.18-10smp, rbase=2, rroot=2.4,
arch=i686, sfx=, variant=optimized
ERROR: Can not locate an M4 program
Making all in:
/extra/sendmail/sendmail-8.12.6/libsmutil
Configuration: pfx=, os=Linux, rel=2.4.18-10smp, rbase=2, rroot=2.4,
arch=i686, sfx=, variant=optimized
ERROR: Can not locate an M4 program
Making all in:
/extra/sendmail/sendmail-8.12.6/libsmdb
Configuration: pfx=, os=Linux, rel=2.4.18-10smp, rbase=2, rroot=2.4,
arch=i686, sfx=, variant=optimized
ERROR: Can not locate an M4 program

Thanks,

Brian