diff --git a/openbsc/src/gsm_04_08_utils.c b/openbsc/src/gsm_04_08_utils.c
index e95d426..821bde2 100644
--- a/openbsc/src/gsm_04_08_utils.c
+++ b/openbsc/src/gsm_04_08_utils.c
@@ -591,6 +591,8 @@
 	gsm48_chan_desc(&ass->chan_desc, lchan);
 	ass->power_command = power_command;
 
+	msgb_tv_put(msg, GSM48_IE_CHANMODE_1, lchan->tch_mode);
+
 	/* in case of multi rate we need to attach a config */
 	if (lchan->tch_mode == GSM48_CMODE_SPEECH_AMR) {
 		if (lchan->mr_conf.ver == 0) {