diff --git a/openbsc/include/openbsc/gsm_04_08.h b/openbsc/include/openbsc/gsm_04_08.h
index ae13581..2afc9c5 100644
--- a/openbsc/include/openbsc/gsm_04_08.h
+++ b/openbsc/include/openbsc/gsm_04_08.h
@@ -754,4 +754,6 @@
 int gsm48_paging_extract_mi(struct msgb *msg, char *mi_string, u_int8_t *mi_type);
 int gsm48_handle_paging_resp(struct msgb *msg, struct gsm_subscriber *subscr);
 
+int gsm48_lchan_modify(struct gsm_lchan *lchan, u_int8_t lchan_mode);
+
 #endif
diff --git a/openbsc/src/gsm_04_08.c b/openbsc/src/gsm_04_08.c
index 2373965..a29d036 100644
--- a/openbsc/src/gsm_04_08.c
+++ b/openbsc/src/gsm_04_08.c
@@ -1087,34 +1087,6 @@
 	return gsm0408_authorize(lchan, msg);
 }
 
-/* 9.1.5 Channel mode modify: Modify the mode on the MS side */
-int gsm48_tx_chan_mode_modify(struct gsm_lchan *lchan, u_int8_t mode)
-{
-	struct msgb *msg = gsm48_msgb_alloc();
-	struct gsm48_hdr *gh = (struct gsm48_hdr *) msgb_put(msg, sizeof(*gh));
-	struct gsm48_chan_mode_modify *cmm =
-		(struct gsm48_chan_mode_modify *) msgb_put(msg, sizeof(*cmm));
-	u_int16_t arfcn = lchan->ts->trx->arfcn & 0x3ff;
-
-	DEBUGP(DRR, "-> CHANNEL MODE MODIFY mode=0x%02x\n", mode);
-
-	lchan->tch_mode = mode;
-	msg->lchan = lchan;
-	gh->proto_discr = GSM48_PDISC_RR;
-	gh->msg_type = GSM48_MT_RR_CHAN_MODE_MODIF;
-
-	/* fill the channel information element, this code
-	 * should probably be shared with rsl_rx_chan_rqd() */
-	cmm->chan_desc.chan_nr = lchan2chan_nr(lchan);
-	cmm->chan_desc.h0.tsc = lchan->ts->trx->bts->tsc;
-	cmm->chan_desc.h0.h = 0;
-	cmm->chan_desc.h0.arfcn_high = arfcn >> 8;
-	cmm->chan_desc.h0.arfcn_low = arfcn & 0xff;
-	cmm->mode = mode;
-
-	return gsm48_sendmsg(msg, NULL);
-}
-
 #if 0
 static u_int8_t to_bcd8(u_int8_t val)
 {
@@ -3167,22 +3139,11 @@
 	return mncc_recvmsg(trans->subscr->net, trans, MNCC_USERINFO_IND, &user);
 }
 
-static int gsm48_lchan_modify(struct gsm_trans *trans, void *arg)
+static int _gsm48_lchan_modify(struct gsm_trans *trans, void *arg)
 {
 	struct gsm_mncc *mode = arg;
-	int rc;
 
-	rc = gsm48_tx_chan_mode_modify(trans->lchan, mode->lchan_mode);
-	if (rc < 0)
-		return rc;
-
-	/* FIXME: we not only need to do this after mode modify, but
-	 * also after channel activation */
-	if (is_ipaccess_bts(trans->lchan->ts->trx->bts) &&
-	    mode->lchan_mode != GSM48_CMODE_SIGN)
-		rc = rsl_ipacc_bind(trans->lchan);
-
-	return rc;
+	return gsm48_lchan_modify(trans->lchan, mode->lchan_mode);
 }
 
 static struct downstate {
@@ -3240,7 +3201,7 @@
 	 MNCC_REL_REQ, gsm48_cc_tx_release},
 	/* special */
 	{ALL_STATES,
-	 MNCC_LCHAN_MODIFY, gsm48_lchan_modify},
+	 MNCC_LCHAN_MODIFY, _gsm48_lchan_modify},
 };
 
 #define DOWNSLLEN \
diff --git a/openbsc/src/gsm_04_08_utils.c b/openbsc/src/gsm_04_08_utils.c
index 358212f..598775c 100644
--- a/openbsc/src/gsm_04_08_utils.c
+++ b/openbsc/src/gsm_04_08_utils.c
@@ -514,3 +514,48 @@
 
 	return gsm48_sendmsg(msg, NULL);
 }
+
+/* 9.1.5 Channel mode modify: Modify the mode on the MS side */
+int gsm48_tx_chan_mode_modify(struct gsm_lchan *lchan, u_int8_t mode)
+{
+	struct msgb *msg = gsm48_msgb_alloc();
+	struct gsm48_hdr *gh = (struct gsm48_hdr *) msgb_put(msg, sizeof(*gh));
+	struct gsm48_chan_mode_modify *cmm =
+		(struct gsm48_chan_mode_modify *) msgb_put(msg, sizeof(*cmm));
+	u_int16_t arfcn = lchan->ts->trx->arfcn & 0x3ff;
+
+	DEBUGP(DRR, "-> CHANNEL MODE MODIFY mode=0x%02x\n", mode);
+
+	lchan->tch_mode = mode;
+	msg->lchan = lchan;
+	gh->proto_discr = GSM48_PDISC_RR;
+	gh->msg_type = GSM48_MT_RR_CHAN_MODE_MODIF;
+
+	/* fill the channel information element, this code
+	 * should probably be shared with rsl_rx_chan_rqd() */
+	cmm->chan_desc.chan_nr = lchan2chan_nr(lchan);
+	cmm->chan_desc.h0.tsc = lchan->ts->trx->bts->tsc;
+	cmm->chan_desc.h0.h = 0;
+	cmm->chan_desc.h0.arfcn_high = arfcn >> 8;
+	cmm->chan_desc.h0.arfcn_low = arfcn & 0xff;
+	cmm->mode = mode;
+
+	return gsm48_sendmsg(msg, NULL);
+}
+
+int gsm48_lchan_modify(struct gsm_lchan *lchan, u_int8_t lchan_mode)
+{
+	int rc;
+
+	rc = gsm48_tx_chan_mode_modify(lchan, lchan_mode);
+	if (rc < 0)
+		return rc;
+
+	/* FIXME: we not only need to do this after mode modify, but
+	 * also after channel activation */
+	if (is_ipaccess_bts(lchan->ts->trx->bts) && lchan_mode != GSM48_CMODE_SIGN)
+		rc = rsl_ipacc_bind(lchan);
+
+	return rc;
+}
+