diff --git a/src/knot/server/udp-handler.c b/src/knot/server/udp-handler.c
index 14707a6e6a2bc01dd3635bd589cc424273cde1f3..fc4e9b1d7eb025ac99be4dd8f3a040960271f277 100644
--- a/src/knot/server/udp-handler.c
+++ b/src/knot/server/udp-handler.c
@@ -491,7 +491,7 @@ void __attribute__ ((constructor)) udp_master_init()
 #ifdef MSG_WAITFORONE
 	/* Check for recvmmsg() support. */
 	if (dlsym(RTLD_DEFAULT, "recvmmsg") != 0) {
-		int r = recvmmsg(-1, NULL, 0, 0, 0);
+		int r = recvmmsg(0, NULL, 0, 0, 0);
 		if (errno != ENOSYS) {
 			_udp_master = udp_master_recvmmsg;
 		}