diff --git a/include/openbsc/abis_rsl.h b/include/openbsc/abis_rsl.h
index b6d9a9d..532595b 100644
--- a/include/openbsc/abis_rsl.h
+++ b/include/openbsc/abis_rsl.h
@@ -379,7 +379,7 @@
 		      u_int8_t bs_power, u_int8_t ms_power,
 		      u_int8_t ta);
 int rsl_chan_activate_lchan(struct gsm_lchan *lchan, u_int8_t act_type, 
-			    u_int8_t ta);
+			    u_int8_t ta, u_int8_t mode);
 int rsl_chan_mode_modify_req(struct gsm_lchan *ts);
 int rsl_paging_cmd(struct gsm_bts *bts, u_int8_t paging_group, u_int8_t len,
 		   u_int8_t *ms_ident, u_int8_t chan_needed);