diff --git a/library/DIAMETER_Emulation.ttcn b/library/DIAMETER_Emulation.ttcn
index d9d9f7a9d..f16acae97 100644
--- a/library/DIAMETER_Emulation.ttcn
+++ b/library/DIAMETER_Emulation.ttcn
@@ -258,6 +258,7 @@ runs on DIAMETER_Emulation_CT return PDU_DIAMETER {
 	var DIAMETER_RecvFrom mrf;
 
 	DIAMETER.send(t_DIAMETER_Send(g_diameter_conn_id, tx));
+	T.start;
 	alt {
 	[] DIAMETER.receive(tr_DIAMETER_RecvFrom_R(rx_t)) -> value mrf { }
 	[] DIAMETER.receive(tr_DIAMETER_RecvFrom_R(?)) -> value mrf {