Where is DINODE_SIZE defined?

all ===> sbin/fsirand
cc -O  -Wall -Wstrict-prototypes -Wmissing-prototypes -Wpointer-arith
-Werror   -c /usr/src/sbin/fsirand/fsirand.c
/usr/src/sbin/fsirand/fsirand.c: In function `fixinodes':
/usr/src/sbin/fsirand/fsirand.c:142: `DINODE_SIZE' undeclared (first

I had a look around /usr/include to no avail...
... yet it appears in eg. src/sys/ufs/ffs/ffs_inode.c, and kernels
compile fine! The above was with a make build, so make includes
happened, and was supped this morning.

Cheers,

Patrick