diff --git a/samples/bpf/tcp_basertt_kern.c b/samples/bpf/tcp_basertt_kern.c
index 4bf4fc597db9..653d233714ad 100644
--- a/samples/bpf/tcp_basertt_kern.c
+++ b/samples/bpf/tcp_basertt_kern.c
@@ -54,7 +54,7 @@ int bpf_basertt(struct bpf_sock_ops *skops)
 		case BPF_SOCK_OPS_BASE_RTT:
 			n = bpf_getsockopt(skops, SOL_TCP, TCP_CONGESTION,
 					   cong, sizeof(cong));
-			if (!n && !__builtin_memcmp(cong, nv, sizeof(nv)+1)) {
+			if (!n && !__builtin_memcmp(cong, nv, sizeof(nv))) {
 				/* Set base_rtt to 80us */
 				rv = 80;
 			} else if (n) {