diff --git a/msc/MSC_Tests.ttcn b/msc/MSC_Tests.ttcn
index 16f7b9b..40e0720 100644
--- a/msc/MSC_Tests.ttcn
+++ b/msc/MSC_Tests.ttcn
@@ -330,6 +330,11 @@
 	f_vty_config(MSCVTY, "network", "authentication optional");
 	f_vty_config(MSCVTY, "msc", "assign-tmsi");
 	f_vty_config(MSCVTY, "network", "encryption a5 0");
+	if (osmux) {
+		f_vty_config(MSCVTY, "msc", "osmux on");
+	} else {
+		f_vty_config(MSCVTY, "msc", "osmux off");
+	}
 }
 
 /* Initialize for a direct connection to BSSAP. This function is an alternative
@@ -1746,7 +1751,6 @@
 testcase TC_lu_and_mt_call_osmux() runs on MTC_CT {
 	var BSC_ConnHdlr vc_conn;
 	f_init(1, false, true, true);
-	f_vty_config(MSCVTY, "msc", "osmux on");
 
 	vc_conn := f_start_handler(refers(f_tc_lu_and_mt_call), 39, 0, true, true);
 	vc_conn.done;