diff --git a/tools/testing/selftests/bpf/cgroup_helpers.c b/tools/testing/selftests/bpf/cgroup_helpers.c
index 4d74f3c4619b..0fb910df5387 100644
--- a/tools/testing/selftests/bpf/cgroup_helpers.c
+++ b/tools/testing/selftests/bpf/cgroup_helpers.c
@@ -98,7 +98,7 @@ static int enable_all_controllers(char *cgroup_path)
  */
 int setup_cgroup_environment(void)
 {
-	char cgroup_workdir[PATH_MAX + 1];
+	char cgroup_workdir[PATH_MAX - 24];
 
 	format_cgroup_path(cgroup_workdir, "");