diff --git a/usr.sbin/tcpdmatch/Makefile b/usr.sbin/tcpdmatch/Makefile
index 6bc67dcb5c3e..161d54b1680e 100644
--- a/usr.sbin/tcpdmatch/Makefile
+++ b/usr.sbin/tcpdmatch/Makefile
@@ -8,7 +8,7 @@ PROG=	tcpdmatch
 MAN=	tcpdmatch.8
 SRCS=	tcpdmatch.c fakelog.c inetcf.c scaffold.c
 
-CFLAGS=	-DREAL_DAEMON_DIR=\"/usr/libexec\" \
+CFLAGS+=-DREAL_DAEMON_DIR=\"/usr/libexec\" \
 	-DSEVERITY=LOG_INFO -DRFC931_TIMEOUT=10
 .if !defined(NOINET6)
 CFLAGS+=-DINET6