diff --git a/tools/testing/selftests/cgroup/cgroup_util.h b/tools/testing/selftests/cgroup/cgroup_util.h
index 82e59cdf16e77..4f66d10626d29 100644
--- a/tools/testing/selftests/cgroup/cgroup_util.h
+++ b/tools/testing/selftests/cgroup/cgroup_util.h
@@ -2,9 +2,9 @@
 #include <stdbool.h>
 #include <stdlib.h>
 
-#define PAGE_SIZE 4096
+#include "../kselftest.h"
 
-#define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]))
+#define PAGE_SIZE 4096
 
 #define MB(x) (x << 20)