diff --git a/openbsc/include/openbsc/gb_proxy.h b/openbsc/include/openbsc/gb_proxy.h
index 3b695e5..db236b5 100644
--- a/openbsc/include/openbsc/gb_proxy.h
+++ b/openbsc/include/openbsc/gb_proxy.h
@@ -37,4 +37,6 @@
 /* Main input function for Gb proxy */
 int gbprox_rcvmsg(struct msgb *msg, struct gprs_nsvc *nsvc, uint16_t ns_bvci);
 
+int gbprox_signal(unsigned int subsys, unsigned int signal,
+		  void *handler_data, void *signal_data);
 #endif