diff --git a/suites/aoip_ussd/assert_extension.py b/suites/aoip_ussd/assert_extension.py
index 5204be8..181f07f 100755
--- a/suites/aoip_ussd/assert_extension.py
+++ b/suites/aoip_ussd/assert_extension.py
@@ -7,9 +7,9 @@
 bts = suite.bts()
 mgcpgw = suite.mgcpgw(bts_ip=bts.remote_addr())
 mgw_bsc = suite.mgw()
-msc = suite.msc(hlr, mgcpgw)
-bsc = suite.bsc(msc, mgw_bsc)
 stp = suite.stp()
+msc = suite.msc(hlr, mgcpgw, stp)
+bsc = suite.bsc(msc, mgw_bsc, stp)
 ms = suite.modem()
 
 hlr.start()