diff --git a/arch/xtensa/boot/Makefile b/arch/xtensa/boot/Makefile
index 40aa55b485be..70fd1453e172 100644
--- a/arch/xtensa/boot/Makefile
+++ b/arch/xtensa/boot/Makefile
@@ -14,7 +14,7 @@ HOSTFLAGS	+= -Iarch/$(ARCH)/boot/include
 
 BIG_ENDIAN	:= $(shell echo -e __XTENSA_EB__ | $(CC) -E - | grep -v "\#")
 
-export EXTRA_CFLAGS
+export ccflags-y
 export BIG_ENDIAN
 
 subdir-y	:= lib
diff --git a/arch/xtensa/boot/lib/Makefile b/arch/xtensa/boot/lib/Makefile
index d3d2aa2d883a..ad8952e8a07f 100644
--- a/arch/xtensa/boot/lib/Makefile
+++ b/arch/xtensa/boot/lib/Makefile
@@ -6,7 +6,7 @@ zlib	:= inffast.c inflate.c inftrees.c
 
 lib-y	+= $(zlib:.c=.o) zmem.o
 
-EXTRA_CFLAGS	+= -Ilib/zlib_inflate
+ccflags-y	:= -Ilib/zlib_inflate
 
 quiet_cmd_copy_zlib = COPY    $@
       cmd_copy_zlib = cat $< > $@