diff --git a/daemon/codec.c b/daemon/codec.c
index 9579a5a93..506730f2c 100644
--- a/daemon/codec.c
+++ b/daemon/codec.c
@@ -622,14 +622,16 @@ static struct rtp_payload_type *codec_make_payload_type(const str *codec, struct
 	const codec_def_t *dec = codec_find(codec);
 	if (!dec)
 		return NULL;
-	const struct rtp_payload_type *rfc_pt = rtp_get_rfc_codec(codec);
-	if (!rfc_pt)
-		return codec_make_dynamic_payload_type(dec, call);
-
-	struct rtp_payload_type *ret = __rtp_payload_type_copy(rfc_pt);
-	ret->codec_def = dec;
+	if (dec->rfc_payload_type >= 0) {
+		const struct rtp_payload_type *rfc_pt = rtp_get_rfc_payload_type(dec->rfc_payload_type);
+		if (rfc_pt) {
+			struct rtp_payload_type *ret = __rtp_payload_type_copy(rfc_pt);
+			ret->codec_def = dec;
+			return ret;
+		}
+	}
+	return codec_make_dynamic_payload_type(dec, call);
 
-	return ret;
 }
 
 
diff --git a/lib/codeclib.c b/lib/codeclib.c
index 0c24607f1..99b261321 100644
--- a/lib/codeclib.c
+++ b/lib/codeclib.c
@@ -7,6 +7,7 @@
 #include "log.h"
 #include "loglib.h"
 #include "resample.h"
+#include "rtplib.h"
 
 
 
@@ -556,6 +557,12 @@ void codeclib_init() {
 		str_init(&def->rtpname_str, (char *) def->rtpname);
 		assert(g_hash_table_lookup(codecs_ht, &def->rtpname_str) == NULL);
 		g_hash_table_insert(codecs_ht, &def->rtpname_str, def);
+
+		const struct rtp_payload_type *pt = rtp_get_rfc_codec(&def->rtpname_str);
+		if (pt)
+			def->rfc_payload_type = pt->payload_type;
+		else
+			def->rfc_payload_type = -1;
 	}
 }
 
diff --git a/lib/codeclib.h b/lib/codeclib.h
index 885d92198..336053653 100644
--- a/lib/codeclib.h
+++ b/lib/codeclib.h
@@ -40,7 +40,9 @@ struct codec_def_s {
 	const int default_ptime;
 	packetizer_f * const packetizer;
 	const int bits_per_sample;
+
 	str rtpname_str;
+	int rfc_payload_type;
 };
 
 struct format_s {
diff --git a/lib/rtplib.c b/lib/rtplib.c
index baccb0996..cab180bc8 100644
--- a/lib/rtplib.c
+++ b/lib/rtplib.c
@@ -130,7 +130,7 @@ const struct rtp_payload_type *rtp_get_rfc_payload_type(unsigned int type) {
 	return rtp_pt;
 }
 
-// XXX use hash table
+// for one-time init only - better use rtp_get_rfc_payload_type(codec_def->rfc_payload_type)
 const struct rtp_payload_type *rtp_get_rfc_codec(const str *codec) {
 	for (int i = 0; i < num_rfc_rtp_payload_types; i++) {
 		if (!rfc_rtp_payload_types[i].encoding.s)