diff --git a/gbproxy/GBProxy_Tests.ttcn b/gbproxy/GBProxy_Tests.ttcn
index af9646c..e12d69f 100644
--- a/gbproxy/GBProxy_Tests.ttcn
+++ b/gbproxy/GBProxy_Tests.ttcn
@@ -1105,7 +1105,7 @@
 			ts_BSSGP_DL_UD(g_pars.tlli, payload, omit, ts_BSSGP_IMSI(g_pars.imsi));
 		/* we cannot use pdu_tx as there are some subtle differences in the length field :/ */
 		var template (present) PDU_BSSGP pdu_rx :=
-			tr_BSSGP_DL_UD(g_pars.tlli, payload, ts_BSSGP_IMSI(g_pars.imsi));
+			tr_BSSGP_DL_UD(g_pars.tlli, payload, tr_BSSGP_IMSI(g_pars.imsi));
 
 		log("DL-UNITDATA(payload_size=", i);
 		f_sgsn2pcu(pdu_tx, pdu_rx);