diff --git a/tools/testing/selftests/Makefile b/tools/testing/selftests/Makefile
index 80e5498eab92..5d9d4ddccccb 100644
--- a/tools/testing/selftests/Makefile
+++ b/tools/testing/selftests/Makefile
@@ -129,11 +129,11 @@ ifneq ($(KBUILD_OUTPUT),)
   # $(realpath ...) resolves symlinks
   abs_objtree := $(realpath $(abs_objtree))
   BUILD := $(abs_objtree)/kselftest
-  KHDR_INCLUDES := -I${abs_objtree}/usr/include
+  KHDR_INCLUDES := -isystem ${abs_objtree}/usr/include
 else
   BUILD := $(CURDIR)
   abs_srctree := $(shell cd $(top_srcdir) && pwd)
-  KHDR_INCLUDES := -I${abs_srctree}/usr/include
+  KHDR_INCLUDES := -isystem ${abs_srctree}/usr/include
   DEFAULT_INSTALL_HDR_PATH := 1
 endif