diff --git a/tools/testing/selftests/bpf/cgroup_helpers.c b/tools/testing/selftests/bpf/cgroup_helpers.c
index cf16948aad4a..6af24f9a780d 100644
--- a/tools/testing/selftests/bpf/cgroup_helpers.c
+++ b/tools/testing/selftests/bpf/cgroup_helpers.c
@@ -44,7 +44,7 @@
  */
 int setup_cgroup_environment(void)
 {
-	char cgroup_workdir[PATH_MAX + 1];
+	char cgroup_workdir[PATH_MAX - 24];
 
 	format_cgroup_path(cgroup_workdir, "");