diff --git a/usr/include/Makefile b/usr/include/Makefile
index a8619aa85c87..fdc79cffcc97 100644
--- a/usr/include/Makefile
+++ b/usr/include/Makefile
@@ -8,7 +8,7 @@
 # We cannot go as far as adding -Wpedantic since it emits too many warnings.
 UAPI_CFLAGS := -std=c90 -Werror=implicit-function-declaration
 
-override c_flags = $(KBUILD_USERCFLAGS) $(UAPI_CFLAGS) -Wp,-MMD,$(depfile) -I $(obj) -I $(srctree)/usr/dummy-include
+override c_flags = $(KBUILD_USERCFLAGS) $(UAPI_CFLAGS) -Wp,-MMD,$(depfile) -I $(obj)
 
 # The following are excluded for now because they fail to build.
 #
@@ -145,7 +145,7 @@ target-can-compile = $(and $(filter-out $(no-header-test), $*.h), \
 quiet_cmd_hdrtest = HDRTEST $<
       cmd_hdrtest = \
 		$(CC) $(c_flags) -fsyntax-only -Werror -x c /dev/null \
-			$(if $(target-no-libc), -nostdinc) \
+			$(if $(target-no-libc), -nostdinc, -I $(srctree)/usr/dummy-include) \
 			$(if $(target-can-compile), -include $< -include $<); \
 		$(PERL) $(src)/headers_check.pl $(obj) $<; \
 		touch $@