diff --git a/pgw/PGW_Tests.ttcn b/pgw/PGW_Tests.ttcn
index 02c28cc..1a02c4d 100644
--- a/pgw/PGW_Tests.ttcn
+++ b/pgw/PGW_Tests.ttcn
@@ -685,8 +685,32 @@
 	vc_conn.done;
 }
 
+/* Test charging over Gy interface. */
+private function f_TC_gy_charging_cc_time() runs on PGW_Session_CT {
+	var default d;
 
+	f_create_session();
 
+	/* We should receive an update even if no traffic is sent: */
+	as_DIA_Gy_CCR(UPDATE_REQUEST);
+
+	d := activate(as_DIA_Gy_CCR(UPDATE_REQUEST));
+	f_ping4(mp_ping_hostname);
+	/* Let the CCA reach the GGSN */
+	f_sleep(0.5);
+	deactivate(d);
+
+	f_delete_session(omit, g_teic, '10'O);
+	setverdict(pass);
+}
+testcase TC_gy_charging_cc_time() runs on PGW_Test_CT {
+	var PGW_Session_CT vc_conn;
+	var SessionPars pars := valueof(t_SessionPars('001010123456789'H, "tun23"));
+	pars.gy_validity_time := 3; /* Grant access for 3 seconds, needs to be re-validated afterwards */
+	f_init();
+	vc_conn := f_start_handler(refers(f_TC_gy_charging_cc_time), pars);
+	vc_conn.done;
+}
 
 control {
 	execute( TC_tx_echo() );
@@ -695,6 +719,7 @@
 	execute( TC_createSession_ping4_256() );
 	execute( TC_createSession_deleteSession() );
 	execute( TC_deleteSession_unknown() );
+	execute( TC_gy_charging_cc_time() );
 }