diff --git a/daemon/call.c b/daemon/call.c
index e6cb84c2e..50d479ba3 100644
--- a/daemon/call.c
+++ b/daemon/call.c
@@ -2429,13 +2429,13 @@ void codecs_offer_answer(struct call_media *media, struct call_media *other_medi
 		codec_tracker_update(&media->codecs);
 
 		// set up handlers
-		codec_handlers_update(media, other_media, flags, sp , NULL);
+		codec_handlers_update(media, other_media, .flags = flags, .sp = sp);
 
 		// updating the handlers may have removed some codecs, so run update the supp codecs again
 		codec_tracker_update(&media->codecs);
 
 		// finally set up handlers again based on final results
-		codec_handlers_update(media, other_media, flags, sp, dialogue[1]);
+		codec_handlers_update(media, other_media, .flags = flags, .sp = sp, .sub = dialogue[1]);
 	}
 	else {
 		// answer
@@ -2465,7 +2465,7 @@ void codecs_offer_answer(struct call_media *media, struct call_media *other_medi
 		// update callee side codec handlers again (second pass after the offer) as we
 		// might need to update some handlers, e.g. when supplemental codecs have been
 		// rejected
-		codec_handlers_update(other_media, media, NULL, NULL, NULL);
+		codec_handlers_update(other_media, media);
 
 		// finally set up our caller side codecs
 		ilogs(codec, LOG_DEBUG, "Codec answer for " STR_FORMAT " #%u",
@@ -2474,15 +2474,15 @@ void codecs_offer_answer(struct call_media *media, struct call_media *other_medi
 		codec_store_answer(&media->codecs, &other_media->codecs, flags);
 
 		// set up handlers
-		codec_handlers_update(media, other_media, flags, sp, NULL);
+		codec_handlers_update(media, other_media, .flags = flags, .sp = sp);
 
 		// updating the handlers may have removed some codecs, so run update the supp codecs again
 		codec_tracker_update(&media->codecs);
 		codec_tracker_update(&other_media->codecs);
 
 		// finally set up handlers again based on final results
-		codec_handlers_update(media, other_media, flags, sp, dialogue[1]);
-		codec_handlers_update(other_media, media, NULL, NULL, dialogue[0]);
+		codec_handlers_update(media, other_media, .flags = flags, .sp = sp, .sub = dialogue[1]);
+		codec_handlers_update(other_media, media, .sub = dialogue[0]);
 
 		// activate audio player if needed (not done by codec_handlers_update without `flags`)
 		audio_player_activate(media);
@@ -3135,7 +3135,7 @@ static int monologue_subscribe_request1(struct call_monologue *src_ml, struct ca
 		codec_store_transcode(&dst_media->codecs, &flags->codec_transcode, &sp->codecs);
 		codec_store_synthesise(&dst_media->codecs, &src_media->codecs);
 
-		codec_handlers_update(dst_media, src_media, flags, sp, NULL);
+		codec_handlers_update(dst_media, src_media, .flags = flags, .sp = sp);
 
 		if (!flags->inactive)
 			bf_copy(&dst_media->media_flags, MEDIA_FLAG_SEND, &src_media->media_flags, SP_FLAG_RECV);
@@ -3251,8 +3251,8 @@ int monologue_subscribe_answer(struct call_monologue *dst_ml, struct sdp_ng_flag
 				return -1;
 		}
 
-		codec_handlers_update(src_media, dst_media, NULL, NULL, NULL);
-		codec_handlers_update(dst_media, src_media, flags, sp, rev_cs);
+		codec_handlers_update(src_media, dst_media);
+		codec_handlers_update(dst_media, src_media, .flags = flags, .sp = sp, .sub = rev_cs);
 
 		__dtls_logic(flags, dst_media, sp);
 
diff --git a/daemon/codec.c b/daemon/codec.c
index 5b76d01d0..43bcab2c0 100644
--- a/daemon/codec.c
+++ b/daemon/codec.c
@@ -991,15 +991,15 @@ static int __codec_handler_eq(const void *a, const void *b) {
 }
 
 // call must be locked in W
-void codec_handlers_update(struct call_media *receiver, struct call_media *sink,
-		const struct sdp_ng_flags *flags, const struct stream_params *sp, struct call_subscription *sub)
+void __codec_handlers_update(struct call_media *receiver, struct call_media *sink,
+		struct chu_args a)
 {
 	ilogs(codec, LOG_DEBUG, "Setting up codec handlers for " STR_FORMAT_M " #%u -> " STR_FORMAT_M " #%u",
 			STR_FMT_M(&receiver->monologue->tag), receiver->index,
 			STR_FMT_M(&sink->monologue->tag), sink->index);
 
-	if (sub)
-		sub->attrs.transcoding = 0;
+	if (a.sub)
+		a.sub->attrs.transcoding = 0;
 	MEDIA_CLEAR(receiver, GENERATOR);
 	MEDIA_CLEAR(sink, GENERATOR);
 
@@ -1010,9 +1010,9 @@ void codec_handlers_update(struct call_media *receiver, struct call_media *sink,
 
 	// non-RTP protocol?
 	if (proto_is(receiver->protocol, PROTO_UDPTL)) {
-		if (codec_handler_udptl_update(receiver, sink, flags)) {
-			if (sub)
-				sub->attrs.transcoding = 1;
+		if (codec_handler_udptl_update(receiver, sink, a.flags)) {
+			if (a.sub)
+				a.sub->attrs.transcoding = 1;
 			return;
 		}
 	}
@@ -1026,9 +1026,9 @@ void codec_handlers_update(struct call_media *receiver, struct call_media *sink,
 
 	// should we transcode to a non-RTP protocol?
 	if (proto_is_not_rtp(sink->protocol)) {
-		if (codec_handler_non_rtp_update(receiver, sink, flags, sp)) {
-			if (sub)
-				sub->attrs.transcoding = 1;
+		if (codec_handler_non_rtp_update(receiver, sink, a.flags, a.sp)) {
+			if (a.sub)
+				a.sub->attrs.transcoding = 1;
 			return;
 		}
 	}
@@ -1048,15 +1048,15 @@ void codec_handlers_update(struct call_media *receiver, struct call_media *sink,
 	bool use_audio_player = !!MEDIA_ISSET(sink, AUDIO_PLAYER);
 	bool implicit_audio_player = false;
 
-	if (flags && flags->audio_player == AP_FORCE)
+	if (a.flags && a.flags->audio_player == AP_FORCE)
 		use_audio_player = true;
-	else if (flags && flags->audio_player == AP_OFF)
+	else if (a.flags && a.flags->audio_player == AP_OFF)
 		use_audio_player = false;
 	else if (rtpe_config.use_audio_player == UAP_ALWAYS)
 		use_audio_player = true;
 	else if (rtpe_config.use_audio_player == UAP_PLAY_MEDIA) {
 		// check for implicitly enabled player
-		if ((flags && flags->opmode == OP_PLAY_MEDIA) || (media_player_is_active(sink->monologue))) {
+		if ((a.flags && a.flags->opmode == OP_PLAY_MEDIA) || (media_player_is_active(sink->monologue))) {
 			use_audio_player = true;
 			implicit_audio_player = true;
 		}
@@ -1088,7 +1088,7 @@ void codec_handlers_update(struct call_media *receiver, struct call_media *sink,
 	if (receiver->monologue->dtmf_trigger.len)
 		do_dtmf_detect = true;
 
-	if (flags && flags->inject_dtmf)
+	if (a.flags && a.flags->inject_dtmf)
 		sink->monologue->inject_dtmf = 1;
 
 	bool use_ssrc_passthrough = MEDIA_ISSET(receiver, ECHO) || sink->monologue->inject_dtmf;
@@ -1195,7 +1195,7 @@ sink_pt_fixed:;
 
 		// XXX synthesise missing supp codecs according to codec tracker XXX needed?
 
-		if (!flags) {
+		if (!a.flags) {
 			// second pass going through the offerer codecs during an answer:
 			// if an answer rejected a supplemental codec that isn't marked for transcoding,
 			// reject it on the sink side as well
@@ -1319,9 +1319,9 @@ sink_pt_fixed:;
 
 transcode:
 		// enable audio player if not explicitly disabled
-		if (rtpe_config.use_audio_player == UAP_TRANSCODING && (!flags || flags->audio_player != AP_OFF))
+		if (rtpe_config.use_audio_player == UAP_TRANSCODING && (!a.flags || a.flags->audio_player != AP_OFF))
 			use_audio_player = true;
-		else if (flags && flags->audio_player == AP_TRANSCODING)
+		else if (a.flags && a.flags->audio_player == AP_TRANSCODING)
 			use_audio_player = true;
 
 		if (use_audio_player) {
@@ -1377,8 +1377,8 @@ next:
 		MEDIA_SET(sink, AUDIO_PLAYER);
 
 	if (is_transcoding) {
-		if (sub)
-			sub->attrs.transcoding = 1;
+		if (a.sub)
+			a.sub->attrs.transcoding = 1;
 
 		if (!use_audio_player) {
 			// we have to translate RTCP packets
@@ -1427,7 +1427,7 @@ next:
 
 			audio_player_setup(sink, pref_dest_codec, rtpe_config.audio_buffer_length,
 					rtpe_config.audio_buffer_delay);
-			if (flags && (flags->early_media || flags->opmode == OP_ANSWER))
+			if (a.flags && (a.flags->early_media || a.flags->opmode == OP_ANSWER))
 				audio_player_activate(sink);
 		}
 	}
@@ -4148,7 +4148,7 @@ void codec_update_all_handlers(struct call_monologue *ml) {
 			struct call_media *sink_media = sink->medias->pdata[i];
 			if (!sink_media)
 				continue;
-			codec_handlers_update(source_media, sink_media, NULL, NULL, NULL);
+			codec_handlers_update(source_media, sink_media);
 		}
 	}
 
@@ -4168,7 +4168,7 @@ void codec_update_all_source_handlers(struct call_monologue *ml, const struct sd
 			struct call_media *sink_media = ml->medias->pdata[i];
 			if (!sink_media)
 				continue;
-			codec_handlers_update(source_media, sink_media, flags, NULL, NULL);
+			codec_handlers_update(source_media, sink_media, .flags = flags);
 		}
 	}
 
diff --git a/daemon/redis.c b/daemon/redis.c
index fc2b9cf41..65e15e606 100644
--- a/daemon/redis.c
+++ b/daemon/redis.c
@@ -1861,7 +1861,7 @@ static int json_link_medias(struct call *c, struct redis_list *medias,
 					continue;
 				other_m->monologue = other_ml;
 				if (other_m->index == med->index) {
-					codec_handlers_update(other_m, med, NULL, NULL, cs);
+					codec_handlers_update(other_m, med, .sub = cs);
 					break;
 				}
 			}
diff --git a/include/codec.h b/include/codec.h
index ca32de089..7eff38985 100644
--- a/include/codec.h
+++ b/include/codec.h
@@ -168,13 +168,20 @@ void codec_init_payload_type(struct rtp_payload_type *, enum media_type);
 void payload_type_clear(struct rtp_payload_type *p);
 
 
+struct chu_args {
+	const struct sdp_ng_flags *flags;
+	const struct stream_params *sp;
+	struct call_subscription *sub;
+};
+#define codec_handlers_update(r, s, ...) \
+	__codec_handlers_update(r, s, (struct chu_args) {__VA_ARGS__})
 
 #ifdef WITH_TRANSCODING
 
 void ensure_codec_def(struct rtp_payload_type *pt, struct call_media *media);
 void codec_handler_free(struct codec_handler **handler);
-void codec_handlers_update(struct call_media *receiver, struct call_media *sink, const struct sdp_ng_flags *,
-		const struct stream_params *, struct call_subscription *);
+__attribute__((nonnull(1, 2)))
+void __codec_handlers_update(struct call_media *receiver, struct call_media *sink, struct chu_args);
 void codec_add_dtmf_event(struct codec_ssrc_handler *ch, int code, int level, uint64_t ts, bool injected);
 uint64_t codec_last_dtmf_event(struct codec_ssrc_handler *ch);
 uint64_t codec_encoder_pts(struct codec_ssrc_handler *ch, struct ssrc_ctx *);
@@ -215,8 +222,7 @@ INLINE struct codec_handler *codec_handler_lookup(GHashTable *ht, int pt, struct
 
 #else
 
-INLINE void codec_handlers_update(struct call_media *receiver, struct call_media *sink,
-		const struct sdp_ng_flags *flags, const struct stream_params *sp, struct call_subscription *sub)
+INLINE void __codec_handlers_update(struct call_media *receiver, struct call_media *sink, struct chu_args a)
 {
 }
 INLINE void codec_handler_free(struct codec_handler **handler) { }