diff --git a/tools/testing/selftests/bpf/progs/fexit_bpf2bpf.c b/tools/testing/selftests/bpf/progs/fexit_bpf2bpf.c
index 983b7c233382..f4bbf87b82dd 100644
--- a/tools/testing/selftests/bpf/progs/fexit_bpf2bpf.c
+++ b/tools/testing/selftests/bpf/progs/fexit_bpf2bpf.c
@@ -53,14 +53,23 @@ int BPF_PROG(test_subprog1, struct sk_buff *skb, int ret)
  *   r0 = *(u32 *)(r1 + 0)
  *   w0 <<= 1
  *   exit
- * In such case the verifier falls back to conservative and
+ * Before llvm23, in such case the verifier falls back to conservative and
  * tracing program can access arguments and return value as u64
- * instead of accurate types.
+ * instead of accurate types. With llvm23, the true signature
+ *   int test_pkt_access_subprog2(volatile struct __sk_buff *skb)
+ * is available in btf.
  */
+#if __clang_major__ >= 23
+struct args_subprog2 {
+	__u64 args[1];
+	__u64 ret;
+};
+#else
 struct args_subprog2 {
 	__u64 args[5];
 	__u64 ret;
 };
+#endif
 __u64 test_result_subprog2 = 0;
 SEC("fexit/test_pkt_access_subprog2")
 int test_subprog2(struct args_subprog2 *ctx)