diff --git a/include/osmocom/msc/codec_sdp_cc_t9n.h b/include/osmocom/msc/codec_sdp_cc_t9n.h
index 150fd265b..8f91c788b 100644
--- a/include/osmocom/msc/codec_sdp_cc_t9n.h
+++ b/include/osmocom/msc/codec_sdp_cc_t9n.h
@@ -44,8 +44,8 @@ extern const struct codec_mapping codec_map[];
 	for ((CODEC_MAPPING) = codec_map; (CODEC_MAPPING) < codec_map + ARRAY_SIZE(codec_map); (CODEC_MAPPING)++)
 
 const struct codec_mapping *codec_mapping_by_speech_ver(enum gsm48_bcap_speech_ver speech_ver);
-const struct codec_mapping *codec_mapping_by_gsm0808_speech_codec_type(enum gsm0808_speech_codec_type sct,
-								       uint16_t cfg);
+const struct codec_mapping *codec_mapping_by_gsm0808_speech_codec_type(enum gsm0808_speech_codec_type sct);
+const struct codec_mapping *codec_mapping_by_gsm0808_speech_codec(const struct gsm0808_speech_codec *sc);
 const struct codec_mapping *codec_mapping_by_perm_speech(enum gsm0808_permitted_speech perm_speech);
 const struct codec_mapping *codec_mapping_by_subtype_name(const char *subtype_name);
 const struct codec_mapping *codec_mapping_by_mgcp_codec(enum mgcp_codecs mgcp);
diff --git a/src/libmsc/codec_sdp_cc_t9n.c b/src/libmsc/codec_sdp_cc_t9n.c
index 4ed5f48e7..22efa5fc0 100644
--- a/src/libmsc/codec_sdp_cc_t9n.c
+++ b/src/libmsc/codec_sdp_cc_t9n.c
@@ -222,7 +222,20 @@ const struct codec_mapping *codec_mapping_by_speech_ver(enum gsm48_bcap_speech_v
 	return NULL;
 }
 
+const struct codec_mapping *codec_mapping_by_gsm0808_speech_codec(const struct gsm0808_speech_codec *sc)
+{
+	const struct codec_mapping *m;
+	foreach_codec_mapping(m) {
+		if (!m->has_gsm0808_speech_codec)
+			continue;
+		if (m->gsm0808_speech_codec.type == sc->type)
+			return m;
+		/* FIXME: evaluate cfg bits? */
+	}
+	return NULL;
+}
 
+const struct codec_mapping *codec_mapping_by_gsm0808_speech_codec_type(enum gsm0808_speech_codec_type sct);
 const struct codec_mapping *codec_mapping_by_gsm0808_speech_codec_type(enum gsm0808_speech_codec_type sct, uint16_t cfg)
 {
 	const struct codec_mapping *m;
@@ -405,7 +418,7 @@ void sdp_audio_codecs_from_speech_codec_list(struct sdp_audio_codecs *ac, const
 	int i;
 	for (i = 0; i < cl->len; i++) {
 		const struct gsm0808_speech_codec *sc = &cl->codec[i];
-		const struct codec_mapping *m = codec_mapping_by_gsm0808_speech_codec_type(sc->type, sc->cfg);
+		const struct codec_mapping *m = codec_mapping_by_gsm0808_speech_codec(sc);
 		if (!m)
 			continue;
 		sdp_audio_codecs_add_copy(ac, &m->sdp);