diff --git a/samples/bpf/xdp1_user.c b/samples/bpf/xdp1_user.c
index ac370e638fa3d2f70bd74f5394c067ceca0b1dde..281dc964de8da35e1d6396e0ad1888000f7b5c64 100644
--- a/samples/bpf/xdp1_user.c
+++ b/samples/bpf/xdp1_user.c
@@ -51,7 +51,7 @@ static void poll_stats(int map_fd, int interval)
 
 		sleep(interval);
 
-		while (bpf_map_get_next_key(map_fd, &key, &key) != -1) {
+		while (bpf_map_get_next_key(map_fd, &key, &key) == 0) {
 			__u64 sum = 0;
 
 			assert(bpf_map_lookup_elem(map_fd, &key, values) == 0);