diff --git a/external/bsd/libarchive/Makefile.inc b/external/bsd/libarchive/Makefile.inc
index 4fcf7db2e..12dc91606 100644
--- a/external/bsd/libarchive/Makefile.inc
+++ b/external/bsd/libarchive/Makefile.inc
@@ -7,7 +7,7 @@ USE_FORT?=	yes # complex string handling
 LIBARCHIVEDIR=	${NETBSDSRCDIR}/external/bsd/libarchive/dist
 
 .if defined(__MINIX)
-CPPFLAGS+=	-I${DESTDIR}/usr/include
+CPPFLAGS+=	-isystem ${DESTDIR}/usr/include
 .endif
 CPPFLAGS+=	-I${NETBSDSRCDIR}/external/bsd/libarchive/include
 CPPFLAGS+=	-DPLATFORM_CONFIG_H=\"config_netbsd.h\"