diff --git a/monitor/nlmon.c b/monitor/nlmon.c
index 9350a3a4..32fa3550 100644
--- a/monitor/nlmon.c
+++ b/monitor/nlmon.c
@@ -1178,12 +1178,10 @@ static struct l_io *open_packet(const char *name)
 	mr.mr_type = PACKET_MR_ALLMULTI;
 
 	if (setsockopt(fd, SOL_PACKET, PACKET_ADD_MEMBERSHIP,
-						&mr, sizeof(mr) < 0)) {
+						&mr, sizeof(mr)) < 0) {
 		perror("Failed to enable all multicast");
-		if (errno != EINVAL) {
-			close(fd);
-			return NULL;
-		}
+		close(fd);
+		return NULL;
 	}
 
 	io = l_io_new(fd);