diff --git a/src/libmsc/gsm_04_08_cc.c b/src/libmsc/gsm_04_08_cc.c
index 93b4995dd..abf604f25 100644
--- a/src/libmsc/gsm_04_08_cc.c
+++ b/src/libmsc/gsm_04_08_cc.c
@@ -865,34 +865,22 @@ static int gsm48_cc_tx_setup_set_transaction_id(struct gsm_trans *trans)
 	return 0;
 }
 
-static int gsm48_cc_tx_setup(struct gsm_trans *trans, void *arg)
+/* MT call leg is starting. Gather all codecs information so far known.
+ * (Usually) paging has succeeded, and now we're processing the MNCC Setup from
+ * the remote MO call leg. Initialize the codecs filter with this side's BSS'
+ * codec list, received at Complete Layer 3. We haven't received the MT MS's
+ * Bearer Capabilities yet; the Bearer Capabilities handled here are actually
+ * the remote call leg's Bearer Capabilities. */
+static int gsm48_cc_tx_setup_select_codecs(struct gsm_trans *trans, const struct gsm_mncc *setup)
 {
-	struct msgb *msg;
-	struct gsm48_hdr *gh;
-	struct gsm_mncc *setup = arg;
-	int rc;
-	struct gsm_mncc_bearer_cap bearer_cap;
-
-	rc = gsm48_cc_tx_setup_set_transaction_id(trans);
-	if (rc < 0)
-		goto error;
-
-	gsm48_start_cc_timer(trans, 0x303, GSM48_T303);
-
-	/* MT call leg is starting. Gather all codecs information so far known.
-	 * (Usually) paging has succeeded, and now we're processing the MNCC Setup from the remote MO call leg.
-	 * Initialize the codecs filter with this side's BSS' codec list, received at Complete Layer 3.
-	 * We haven't received the MT MS's Bearer Capabilities yet; the Bearer Capabilities handled here are
-	 * actually the remote call leg's Bearer Capabilities. */
 	trans_cc_filter_init(trans);
 	trans_cc_filter_set_ran(trans, trans->msc_a->c.ran->type);
 	trans_cc_filter_set_bss(trans, trans->msc_a);
-	if (setup->fields & MNCC_F_BEARER_CAP)
-		trans->bearer_cap.transfer = setup->bearer_cap.transfer;
 
 	switch (trans->bearer_cap.transfer) {
 	case GSM48_BCAP_ITCAP_SPEECH:
-		/* if SDP is included in the MNCC, take that as definitive list of remote audio codecs. */
+		/* if SDP is included in the MNCC, take that as definitive list
+		 * of remote audio codecs. */
 		rx_mncc_sdp(trans, setup->msg_type, setup->sdp,
 			    (setup->fields & MNCC_F_BEARER_CAP) ? &setup->bearer_cap : NULL);
 		/* rx_mncc_sdp() has called trans_cc_filter_run(trans); */
@@ -915,9 +903,33 @@ static int gsm48_cc_tx_setup(struct gsm_trans *trans, void *arg)
 	default:
 		LOG_TRANS(trans, LOGL_ERROR, "Handling of information transfer capability %d not implemented\n",
 			  trans->bearer_cap.transfer);
-		break;
+		return -1;
 	}
 
+	return 0;
+}
+
+static int gsm48_cc_tx_setup(struct gsm_trans *trans, void *arg)
+{
+	struct msgb *msg;
+	struct gsm48_hdr *gh;
+	struct gsm_mncc *setup = arg;
+	int rc;
+	struct gsm_mncc_bearer_cap bearer_cap;
+
+	rc = gsm48_cc_tx_setup_set_transaction_id(trans);
+	if (rc < 0)
+		goto error;
+
+	gsm48_start_cc_timer(trans, 0x303, GSM48_T303);
+
+	if (setup->fields & MNCC_F_BEARER_CAP)
+		trans->bearer_cap.transfer = setup->bearer_cap.transfer;
+
+	rc = gsm48_cc_tx_setup_select_codecs(trans, setup);
+	if (rc < 0)
+		goto error;
+
 	/* Compose Bearer Capability information that reflects only the codecs (Speech Versions) / CSD bearer services
 	 * remaining after intersecting MS, BSS and remote call leg restrictions. To store in trans for later use, and
 	 * to include in the outgoing CC Setup message. */