diff --git a/bts/BTS_Tests.ttcn b/bts/BTS_Tests.ttcn
index f59cc89..b8c4118 100644
--- a/bts/BTS_Tests.ttcn
+++ b/bts/BTS_Tests.ttcn
@@ -2219,7 +2219,8 @@
 private altstep as_l1_tch_loop() runs on ConnHdlr {
 	var L1ctlMessage l1_dl;
 	[] L1CTL.receive(tr_L1CTL_TRAFFIC_IND(g_chan_nr)) -> value l1_dl {
-		log("TCH received: ", l1_dl.payload.traffic_ind.data);
+		var octetstring data := l1_dl.payload.traffic_ind.data;
+		log("TCH received (len=", lengthof(data), "): ", data);
 
 		/* occasionaly inject FACCH frames into the uplink */
 		if (g_pars.l1_pars.facch_enabled == true and l1_dl.dl_info.frame_nr mod 5 == 0) {
@@ -8319,7 +8320,8 @@
 	Td.start(2.0);
 	alt {
 	[] L1CTL.receive(tr_L1CTL_TRAFFIC_IND(g_chan_nr, frame := pl)) -> value l1_dl {
-		log("TCH received: ", l1_dl.payload.traffic_ind.data);
+		var octetstring data := l1_dl.payload.traffic_ind.data;
+		log("TCH received (len=", lengthof(data), "): ", data);
 		L1CTL.send(ts_L1CTL_TRAFFIC_REQ(g_chan_nr, l1_dl.dl_info.link_id,
 			   l1_dl.payload.traffic_ind.data));
 		setverdict(pass);