diff --git a/bsc/BSC_Tests.ttcn b/bsc/BSC_Tests.ttcn
index 5a22c00..bfab0fa 100644
--- a/bsc/BSC_Tests.ttcn
+++ b/bsc/BSC_Tests.ttcn
@@ -2095,8 +2095,9 @@
 
 	f_statsd_reset();
 
-	/* Establish SDCCH */
+	/* Establish SDCCH (invalid DataIndicator for exp_fail) */
 	ass_cmd.pdu.bssmap.assignmentRequest.channelType := valueof(ts_BSSMAP_IE_ChannelTypeCSD);
+	ass_cmd.pdu.bssmap.assignmentRequest.channelType.speechId_DataIndicator := 'ff'O;
 	f_establish_fully(ass_cmd, exp_fail);
 
 	/* Expect stats to be 0 */