diff --git a/bsc/BSC_Tests.ttcn b/bsc/BSC_Tests.ttcn
index f99d4b006..340d76613 100644
--- a/bsc/BSC_Tests.ttcn
+++ b/bsc/BSC_Tests.ttcn
@@ -3415,6 +3415,20 @@ testcase TC_assignment_fr_a5_4() runs on test_CT {
 	f_shutdown_helper();
 }
 
+/* Allow only A5/4, but omit the Kc128 IE from MSC's msg. Expect Cipher Mode Reject. */
+testcase TC_assignment_fr_a5_4_fail() 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);
+
+	pars.encr := valueof(t_EncrParams('10'O, f_rnd_octstring(8))); // A5/4 support, but Kc128 missing!
+	vc_conn := f_start_handler(refers(f_TC_assignment_a5_not_sup), pars);
+	vc_conn.done;
+	f_shutdown_helper();
+}
+
 /* Expect ASSIGNMENT FAIL if mandatory IE is missing */
 private function f_tc_assignment_fr_a5_1_codec_missing(charstring id) runs on MSC_ConnHdlr {
 	g_pars := f_gen_test_hdlr_pars();
@@ -8943,6 +8957,7 @@ control {
 	}
 	execute( TC_assignment_fr_a5_3() );
 	execute( TC_assignment_fr_a5_4() );
+	execute( TC_assignment_fr_a5_4_fail() );
 	execute( TC_assignment_fr_a5_not_sup() );
 	execute( TC_ciph_mode_a5_0() );
 	execute( TC_ciph_mode_a5_1() );
diff --git a/bsc/expected-results.xml b/bsc/expected-results.xml
index e3a6a87ad..0efc3e075 100644
--- a/bsc/expected-results.xml
+++ b/bsc/expected-results.xml
@@ -48,6 +48,7 @@
   <testcase classname='BSC_Tests' name='TC_assignment_fr_a5_1_codec_missing' time='MASKED'/>
   <testcase classname='BSC_Tests' name='TC_assignment_fr_a5_3' time='MASKED'/>
   <testcase classname='BSC_Tests' name='TC_assignment_fr_a5_4' time='MASKED'/>
+  <testcase classname='BSC_Tests' name='TC_assignment_fr_a5_4_fail' time='MASKED'/>
   <testcase classname='BSC_Tests' name='TC_assignment_fr_a5_not_sup' time='MASKED'/>
   <testcase classname='BSC_Tests' name='TC_ciph_mode_a5_0' time='MASKED'/>
   <testcase classname='BSC_Tests' name='TC_ciph_mode_a5_1' time='MASKED'/>