diff --git a/include/openbsc/gsm_data.h b/include/openbsc/gsm_data.h
index a838c79..c3eea59 100644
--- a/include/openbsc/gsm_data.h
+++ b/include/openbsc/gsm_data.h
@@ -151,6 +151,7 @@
 	void (*update_request_accepted)(struct gsm_bts *, u_int32_t);
 	void (*channel_allocated)(struct gsm_lchan *bts, enum gsm_chreq_reason_t);
 	void (*channel_response)(struct gsm_lchan *, int acked);
+	void (*call_released)(struct gsm_lchan *);
 };
 
 struct gsm_network *gsm_network_init(unsigned int num_bts, u_int16_t country_code,