Index: head/Makefile.inc1
===================================================================
--- head/Makefile.inc1
+++ head/Makefile.inc1
@@ -734,7 +734,7 @@
 # TOOLS_PREFIX set in BMAKE
 XMAKE=		${BMAKE} \
 		TARGET=${TARGET} TARGET_ARCH=${TARGET_ARCH} \
-		MK_CLANG_IS_CC=yes \
+		MK_CLANG_IS_CC=${MK_CLANG_BOOTSTRAP} \
 		MK_GDB=no MK_TESTS=no
 
 # kernel-tools stage