diff --git a/libexec/atf/Makefile.inc b/libexec/atf/Makefile.inc
index b50e14e..e59a413 100644
--- a/libexec/atf/Makefile.inc
+++ b/libexec/atf/Makefile.inc
@@ -25,7 +25,7 @@
 #
 # $FreeBSD: stable/10/libexec/atf/Makefile.inc 271298 2014-09-09 04:00:30Z ngie $
 
-CFLAGS+=	-DHAVE_CONFIG_H
+CXXFLAGS+=	-DHAVE_CONFIG_H
 
 WARNS?=		3
 
diff --git a/libexec/atf/atf-check/Makefile b/libexec/atf/atf-check/Makefile
index 77c11db..7449ddb 100644
--- a/libexec/atf/atf-check/Makefile
+++ b/libexec/atf/atf-check/Makefile
@@ -34,8 +34,8 @@ PROG_CXX=	atf-check
 SRCS=		atf-check.cpp
 MAN=		atf-check.1
 
-CFLAGS+=	-I${ATF}
-CFLAGS+=	-DATF_SHELL='"/bin/sh"'
+CXXFLAGS+=	-I${ATF}
+CXXFLAGS+=	-DATF_SHELL='"/bin/sh"'
 
 LDFLAGS+=	-L${.OBJDIR}/../../../lib/atf/libatf-c++
 LDFLAGS+=	-L${.OBJDIR}/../../../lib/atf/libatf-c