diff --git a/usr.sbin/makefs/ffs/Makefile.inc b/usr.sbin/makefs/ffs/Makefile.inc
index a1e839fd7ab6..cff2c30b67c5 100644
--- a/usr.sbin/makefs/ffs/Makefile.inc
+++ b/usr.sbin/makefs/ffs/Makefile.inc
@@ -1,9 +1,11 @@
 #	$FreeBSD$
 #
 
 .PATH:	${SRCDIR}/ffs ${SRCTOP}/sys/ufs/ffs
 SRCS+=	ffs_alloc.c ffs_balloc.c ffs_bswap.c ffs_subr.c ufs_bmap.c
 SRCS+=	buf.c mkfs.c
 
 # Reach-over source from sys/ufs/ffs
 SRCS+=	ffs_tables.c
+
+CWARNFLAGS.ffs_balloc.c+= -Wno-sign-compare