diff --git a/stp/STP_Tests_M3UA.ttcn b/stp/STP_Tests_M3UA.ttcn
index 9f3bf0c..24b3ae1 100644
--- a/stp/STP_Tests_M3UA.ttcn
+++ b/stp/STP_Tests_M3UA.ttcn
@@ -326,6 +326,12 @@
 	var OptionList opt_list := {};
 	var M3uaConfig m3cfg := mp_m3ua_configs[i];
 
+	/* XXX: M3UA-over-TCP is not supported by osmo-stp <= 1.8.1 */
+	if (not Misc_Helpers.f_osmo_repo_is("nightly") and m3cfg.use_tcp) {
+		log("Not listen()ing m3cfg := ", m3cfg, " (not supported by IUT)");
+		return;
+	}
+
 	if (lengthof(mp_local_m3ua_ip) == 0 ) {
 		setverdict(fail, "Empty local address trying to bind SCTP socket: ",
 			   mp_local_m3ua_ip);
@@ -365,6 +371,12 @@
 	}
 
 	for (i := 0; i < NR_M3UA; i:=i+1) {
+		/* XXX: M3UA-over-TCP is not supported by osmo-stp <= 1.8.1 */
+		if (not Misc_Helpers.f_osmo_repo_is("nightly") and mp_m3ua_configs[i].use_tcp) {
+			log("Not connect()ing m3cfg := ", mp_m3ua_configs[i], " (not supported by IUT)");
+			g_m3ua_conn_id[i] := -1;
+			continue;
+		}
 		map(self:M3UA[i], system:M3UA_CODEC_PT);
 		if (mp_m3ua_configs[i].use_tcp) {
 			f_M3UA_connect_tcp(i);
@@ -392,6 +404,12 @@
 	var PortEvent port_evt;
 
 	for (i := NR_M3UA; i < NR_M3UA+NR_M3UA_SRV; i:=i+1) {
+		/* XXX: M3UA-over-TCP is not supported by osmo-stp <= 1.8.1 */
+		if (not Misc_Helpers.f_osmo_repo_is("nightly") and mp_m3ua_configs[i].use_tcp) {
+			log("Not listen()ing m3cfg := ", mp_m3ua_configs[i], " (not supported by IUT)");
+			g_m3ua_conn_id[i] := -1;
+			continue;
+		}
 		map(self:M3UA[i], system:M3UA_CODEC_PT);
 		/* bind+ listen */
 		f_M3UA_listen(i);