diff --git a/Makefile.inc1 b/Makefile.inc1
index 7f72092d9966..ed9388610f17 100644
--- a/Makefile.inc1
+++ b/Makefile.inc1
@@ -2742,8 +2742,7 @@ CD2CFLAGS+=	-isystem ${XDDESTDIR}/usr/include -L${XDDESTDIR}/usr/lib
 # combined with --sysroot.
 CD2CFLAGS+=	-B${XDDESTDIR}/usr/lib
 # Force using libc++ for external GCC.
-# XXX: This should be checking MK_GNUCXX == no
-.if ${X_COMPILER_VERSION} >= 40800
+.if ${X_COMPILER_TYPE} == gcc && ${X_COMPILER_VERSION} >= 40800
 CD2CXXFLAGS+=	-isystem ${XDDESTDIR}/usr/include/c++/v1 -std=c++11 \
 		-nostdinc++
 .endif
diff --git a/Makefile.libcompat b/Makefile.libcompat
index 3c0aabb2d05f..8542d5b246ae 100644
--- a/Makefile.libcompat
+++ b/Makefile.libcompat
@@ -99,8 +99,7 @@ LIBCOMPATCFLAGS+=	-B${LIBCOMPATTMP}/usr/lib${libcompat}
 # sysroot path which --sysroot does not actually do for headers.
 LIBCOMPATCFLAGS+=	-isystem ${LIBCOMPATTMP}/usr/include
 # Force using libc++ for external GCC.
-# XXX: This should be checking MK_GNUCXX == no
-.if ${X_COMPILER_VERSION} >= 40800 && \
+.if ${X_COMPILER_TYPE} == gcc && ${X_COMPILER_VERSION} >= 40800 && \
     (${MK_CLANG_BOOTSTRAP} == "no" && ${MK_GCC_BOOTSTRAP} == "no")
 LIBCOMPATCXXFLAGS+=	-isystem ${LIBCOMPATTMP}/usr/include/c++/v1 -std=c++11 \
 			-nostdinc++