diff --git a/gbproxy/GBProxy_Tests.ttcn b/gbproxy/GBProxy_Tests.ttcn
index 44b2ac9..6daad53 100644
--- a/gbproxy/GBProxy_Tests.ttcn
+++ b/gbproxy/GBProxy_Tests.ttcn
@@ -597,14 +597,15 @@
 			 float t_guard := 30.0)
 runs on test_CT return BSSGP_ConnHdlr {
 	var BSSGP_ConnHdlr vc_conn;
+	var OCT4 p_tmsi := f_gen_tmsi(imsi_suffix);
 
 	var BSSGP_ConnHdlrPars pars := {
 		imei := f_gen_imei(imsi_suffix),
 		imsi := f_gen_imsi(imsi_suffix),
 		msisdn := f_gen_msisdn(imsi_suffix),
-		p_tmsi := omit,
+		p_tmsi := p_tmsi,
 		p_tmsi_sig := omit,
-		tlli := f_gprs_tlli_random(),
+		tlli := f_gprs_tlli_from_tmsi(p_tmsi, TLLI_LOCAL),
 		tlli_old := omit,
 		ra := omit,
 		pcu := g_pcu,