diff --git a/hlr/HLR_Tests.ttcn b/hlr/HLR_Tests.ttcn
index 753f92ec0..2bf5e5784 100644
--- a/hlr/HLR_Tests.ttcn
+++ b/hlr/HLR_Tests.ttcn
@@ -103,6 +103,7 @@ function f_init_gsup(charstring id, boolean legacy) runs on test_CT {
 
 	ccm_pars := c_IPA_default_ccm_pars;
 	ccm_pars.name := "Osmocom TTCN-3 GSUP Simulator";
+	ccm_pars.ser_nr := "MSC-00-00-00-00-00-00";
 
 	vc_IPA := IPA_Emulation_CT.create(id & "-IPA");
 	log("legacy= ", legacy);