diff --git a/bts/BTS_Tests.ttcn b/bts/BTS_Tests.ttcn
index 1d2a148..0ce611a 100644
--- a/bts/BTS_Tests.ttcn
+++ b/bts/BTS_Tests.ttcn
@@ -3994,13 +3994,13 @@
 
 /* helper function: Set given SI via RSL + validate scheduling.
  * CALLER MUST MAKE SURE TO CHANGE GLOBAL si_cfg! */
-private function f_TC_si_sched() runs on test_CT {
+private function f_TC_si_sched(float duration := 8.0) runs on test_CT {
 	var SystemInformationVectorPerTc si_per_tc;
 	f_init_l1ctl();
 	f_l1_tune(L1CTL);
 
 	/* Sample + Validate Scheduling */
-	si_per_tc := f_l1_sample_si(L1CTL);
+	si_per_tc := f_l1_sample_si(L1CTL, duration);
 	f_validate_si_scheduling(si_cfg, si_per_tc);
 
 	setverdict(pass);
@@ -4051,7 +4051,7 @@
 	f_init();
 	si_cfg.si2quater_present := true;
 	f_rsl_bcch_fill_raw(RSL_SYSTEM_INFO_2quater, '050607a8a0364aa698d72ff424feee0506d5e7fff02043'O);
-	f_TC_si_sched();
+	f_TC_si_sched(16.0);
 	Misc_Helpers.f_shutdown(__BFILE__, __LINE__);
 }
 
@@ -4073,7 +4073,7 @@
 	f_rsl_bcch_fill_raw(RSL_SYSTEM_INFO_2quater, '050607a8a0364aa698d72ff424feee0506d5e7fff02043'O);
 	si_cfg.si13_present := true;
 	f_rsl_bcch_fill_raw(RSL_SYSTEM_INFO_13, '0106009000185a6fc9e08410ab2b2b2b2b2b2b2b2b2b2b'O);
-	f_TC_si_sched();
+	f_TC_si_sched(16.0);
 	Misc_Helpers.f_shutdown(__BFILE__, __LINE__);
 }