diff --git a/bsc/BSC_Tests.ttcn b/bsc/BSC_Tests.ttcn
index 102a7f2..38e591c 100644
--- a/bsc/BSC_Tests.ttcn
+++ b/bsc/BSC_Tests.ttcn
@@ -3415,26 +3415,54 @@
 	f_shutdown_helper();
 }
 
-private function f_tc_assignment_fr_a5_4(charstring id) runs on MSC_ConnHdlr {
-	g_pars := f_gen_test_hdlr_pars();
-	var template PDU_BSSAP exp_compl := f_gen_exp_compl();
-	var PDU_BSSAP ass_cmd := f_gen_ass_req();
-	const OCT8 kc := '0001020304050607'O;
-	const OCT16 kc128 := kc & kc;
+private function f_TC_assignment_a5_not_sup(charstring id) runs on MSC_ConnHdlr {
+	var template PDU_BSSAP exp_ass_cpl := f_gen_exp_compl();
+	var PDU_BSSAP exp_ass_req := f_gen_ass_req();
 
-	ass_cmd.pdu.bssmap.assignmentRequest.channelType := valueof(ts_BSSMAP_IE_ChannelType);
-	ass_cmd.pdu.bssmap.assignmentRequest.codecList := valueof(ts_BSSMAP_IE_CodecList({ts_CodecFR}));
-	f_establish_fully(ass_cmd, exp_compl);
-	f_cipher_mode('10'O, kc, kc128, true);
-	/* TODO: expect GSM0808_CAUSE_CIPHERING_ALGORITHM_NOT_SUPPORTED cause value */
+	exp_ass_req.pdu.bssmap.assignmentRequest.channelType := valueof(ts_BSSMAP_IE_ChannelType);
+	exp_ass_req.pdu.bssmap.assignmentRequest.codecList := valueof(ts_BSSMAP_IE_CodecList({ts_CodecFR}));
+
+	/* this is like the beginning of f_establish_fully(), but only up to ciphering reject */
+
+	var BSSMAP_FIELD_CodecType codecType;
+	timer T := 10.0;
+
+	codecType := exp_ass_req.pdu.bssmap.assignmentRequest.codecList.codecElements[0].codecType;
+	f_MscConnHdlr_init(g_pars.media_nr, host_bts, host_mgw_mgcp, codecType);
+
+	f_create_chan_and_exp();
+	/* we should now have a COMPL_L3 at the MSC */
+
+	var template PDU_BSSAP exp_l3_compl;
+	exp_l3_compl := tr_BSSMAP_ComplL3()
+	if (g_pars.aoip == false) {
+		exp_l3_compl.pdu.bssmap.completeLayer3Information.codecList := omit;
+	} else {
+		exp_l3_compl.pdu.bssmap.completeLayer3Information.codecList := ?;
+	}
+	T.start;
+	alt {
+	[] BSSAP.receive(exp_l3_compl);
+	[] BSSAP.receive(tr_BSSMAP_ComplL3) {
+		Misc_Helpers.f_shutdown(__BFILE__, __LINE__, fail, "Received non-matching COMPLETE LAYER 3 INFORMATION");
+		}
+	[] T.timeout {
+		Misc_Helpers.f_shutdown(__BFILE__, __LINE__, fail, "Timeout waiting for COMPLETE LAYER 3 INFORMATION");
+		}
+	}
+
+	/* Start ciphering, expect Cipher Mode Reject */
+	f_cipher_mode(g_pars.encr.enc_alg, g_pars.encr.enc_key, exp_fail := true);
 }
-testcase TC_assignment_fr_a5_4() runs on test_CT {
+testcase TC_assignment_fr_a5_not_sup() runs on test_CT {
+	var TestHdlrParams pars := f_gen_test_hdlr_pars();
 	var MSC_ConnHdlr vc_conn;
 
 	f_init(1, true);
 	f_sleep(1.0);
 
-	vc_conn := f_start_handler(refers(f_tc_assignment_fr_a5_4));
+	pars.encr := valueof(t_EncrParams('20'O, f_rnd_octstring(8)));
+	vc_conn := f_start_handler(refers(f_TC_assignment_a5_not_sup), pars);
 	vc_conn.done;
 	f_shutdown_helper();
 }
@@ -8891,7 +8919,7 @@
 		execute( TC_assignment_fr_a5_1_codec_missing() );
 	}
 	execute( TC_assignment_fr_a5_3() );
-	execute( TC_assignment_fr_a5_4() );
+	execute( TC_assignment_fr_a5_not_sup() );
 	execute( TC_ciph_mode_a5_0() );
 	execute( TC_ciph_mode_a5_1() );
 	execute( TC_ciph_mode_a5_3() );