diff --git a/Makefile.inc1 b/Makefile.inc1
index ab028a6cf941..ca84c60ec424 100644
--- a/Makefile.inc1
+++ b/Makefile.inc1
@@ -549,8 +549,10 @@ TARGET_ABI=	gnueabi
 XCFLAGS+=	-isystem ${WORLDTMP}/usr/include -L${WORLDTMP}/usr/lib
 # Force using libc++ for external GCC.
 # XXX: This should be checking MK_GNUCXX == no
+.if ${X_COMPILER_VERSION} >= 40800
 XCXXFLAGS+=	-isystem ${WORLDTMP}/usr/include/c++/v1 -std=c++11 \
 		-nostdinc++ -L${WORLDTMP}/../lib/libc++
+.endif
 .else
 TARGET_ABI?=	unknown
 TARGET_TRIPLE?=	${TARGET_ARCH:C/amd64/x86_64/}-${TARGET_ABI}-freebsd11.0
diff --git a/Makefile.libcompat b/Makefile.libcompat
index 4b923bb467b8..3182c8c33b01 100644
--- a/Makefile.libcompat
+++ b/Makefile.libcompat
@@ -81,8 +81,8 @@ LIBCOMPATCFLAGS+=	-B${LIBCOMPATTMP}/usr/lib${libcompat}
 LIBCOMPATCFLAGS+=	-isystem ${LIBCOMPATTMP}/usr/include
 # Force using libc++ for external GCC.
 # XXX: This should be checking MK_GNUCXX == no
-.if ${MK_CROSS_COMPILER} == "no" || \
-    (${MK_CLANG_BOOTSTRAP} == "no" && ${MK_GCC_BOOTSTRAP} == "no")
+.if ${X_COMPILER_VERSION} >= 40800 && (${MK_CROSS_COMPILER} == "no" || \
+    (${MK_CLANG_BOOTSTRAP} == "no" && ${MK_GCC_BOOTSTRAP} == "no"))
 LIBCOMPATCXXFLAGS+=	-isystem ${LIBCOMPATTMP}/usr/include/c++/v1 -std=c++11 \
 			-nostdinc++ -L${LIBCOMPAT_OBJTREE}${.CURDIR}/lib/libc++
 .endif