Index: head/Mk/Uses/localbase.mk
===================================================================
--- head/Mk/Uses/localbase.mk	(revision 397025)
+++ head/Mk/Uses/localbase.mk	(revision 397026)
@@ -1,22 +1,22 @@
 # $FreeBSD$
 #
 # handle enforcing localbase in path
 #
 # Feature:	localbase
 # Usage:	USES=localbase
 # Valid ARGS:	none
 #
 # MAINTAINER:	portmgr@FreeBSD.org
 
 .if !defined(_INCLUDE_USES_LOCALBASE_MK)
 _INCLUDE_USES_LOCALBASE_MK=	yes
 
-CPPFLAGS+=	-I${LOCALBASE}/include
-CFLAGS+=	-I${LOCALBASE}/include
-CXXFLAGS+=	-I${LOCALBASE}/include
+CPPFLAGS+=	-isystem ${LOCALBASE}/include
+CFLAGS+=	-isystem ${LOCALBASE}/include
+CXXFLAGS+=	-isystem ${LOCALBASE}/include
 LDFLAGS+=	-L${LOCALBASE}/lib
 
 # Use CONFIGURE_ENV instead of CMAKE_ARGS because devel/cmake itself also needs
 # this, and CMAKE_ARGS is not used when bootstrapping CMake.
 CONFIGURE_ENV+=	CMAKE_PREFIX_PATH="${LOCALBASE}"
 .endif