diff --git a/samples/bpf/xdp_adjust_tail_kern.c b/samples/bpf/xdp_adjust_tail_kern.c
index ffdd548627f0..da67bcad1c63 100644
--- a/samples/bpf/xdp_adjust_tail_kern.c
+++ b/samples/bpf/xdp_adjust_tail_kern.c
@@ -57,6 +57,7 @@ static __always_inline void swap_mac(void *data, struct ethhdr *orig_eth)
 
 static __always_inline __u16 csum_fold_helper(__u32 csum)
 {
+	csum = (csum & 0xffff) + (csum >> 16);
 	return ~((csum & 0xffff) + (csum >> 16));
 }