diff --git a/Makefile b/Makefile
index f65e282f4a3f..16a23aaaa547 100644
--- a/Makefile
+++ b/Makefile
@@ -568,8 +568,7 @@ ifneq ($(LLVM_IAS),1)
 CLANG_FLAGS	+= -no-integrated-as
 endif
 CLANG_FLAGS	+= -Werror=unknown-warning-option
-KBUILD_CFLAGS	+= $(CLANG_FLAGS)
-KBUILD_AFLAGS	+= $(CLANG_FLAGS)
+KBUILD_CPPFLAGS	+= $(CLANG_FLAGS)
 export CLANG_FLAGS
 endif