diff --git a/usr.sbin/makefs/ffs/Makefile.inc b/usr.sbin/makefs/ffs/Makefile.inc
--- a/usr.sbin/makefs/ffs/Makefile.inc
+++ b/usr.sbin/makefs/ffs/Makefile.inc
@@ -7,3 +7,5 @@
 
 # Reach-over source from sys/ufs/ffs
 SRCS+=	ffs_tables.c
+
+CWARNFLAGS.ffs_balloc.c+= -Wno-sign-compare
diff --git a/usr.sbin/makefs/zfs/Makefile.inc b/usr.sbin/makefs/zfs/Makefile.inc
--- a/usr.sbin/makefs/zfs/Makefile.inc
+++ b/usr.sbin/makefs/zfs/Makefile.inc
@@ -10,3 +10,4 @@
 SRCS+=	nvlist.c
 
 CFLAGS.nvlist.c+= -I${SRCTOP}/stand/libsa -Wno-cast-qual
+CWARNFLAGS.zap.c+= -Wno-sign-compare