diff --git a/pcu/PCU_Tests.ttcn b/pcu/PCU_Tests.ttcn
index a6d3559..ba27e58 100644
--- a/pcu/PCU_Tests.ttcn
+++ b/pcu/PCU_Tests.ttcn
@@ -592,7 +592,7 @@
 
 	/* SGSN sends some DL data, PCU will initiate Packet Downlink
 	 * Assignment on CCCH (PCH). We don't care about the payload. */
-	BSSGP[0].send(ts_BSSGP_DL_UD(ms.tlli, f_rnd_octstring(10)));
+	BSSGP[0].send(ts_BSSGP_DL_UD(ms.tlli, f_rnd_octstring(10), imsi := ts_BSSGP_IMSI(ms.imsi)));
 	f_ms_exp_dl_tbf_ass_ccch(ms);
 
 	/* Make sure that Timing Advance is 0 (the actual value is not known yet).