diff --git a/bsc/BSC_Tests.ttcn b/bsc/BSC_Tests.ttcn
index 4ae90bb..f99d4b0 100644
--- a/bsc/BSC_Tests.ttcn
+++ b/bsc/BSC_Tests.ttcn
@@ -3402,6 +3402,18 @@
 	vc_conn.done;
 	f_shutdown_helper();
 }
+/* Establish a Signalling channel and re-assign to TCH/F with A5/4 encryption. */
+testcase TC_assignment_fr_a5_4() runs on test_CT {
+	var MSC_ConnHdlr vc_conn;
+	var TestHdlrParams pars := f_gen_test_hdlr_pars();
+	pars.encr := valueof(t_EncrParams('10'O, f_rnd_octstring(8), f_rnd_octstring(16)));
+
+	f_init(1, true);
+	f_sleep(1.0);
+	vc_conn := f_start_handler(refers(f_tc_assignment_fr_a5), 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 {
@@ -8930,6 +8942,7 @@
 		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() );