diff --git a/usr.sbin/jail/Makefile b/usr.sbin/jail/Makefile
--- a/usr.sbin/jail/Makefile
+++ b/usr.sbin/jail/Makefile
@@ -11,6 +11,7 @@
 PACKAGE=jail
 
 NO_WMISSING_VARIABLE_DECLARATIONS=
+CWARNFLAGS.jailparse.c=	${NO_WUNUSED_BUT_SET_VARIABLE}
 
 YFLAGS+=-v
 CFLAGS+=-I. -I${.CURDIR}