diff --git a/include/openbsc/signal.h b/include/openbsc/signal.h
index eb4fc8d..e53c194 100644
--- a/include/openbsc/signal.h
+++ b/include/openbsc/signal.h
@@ -28,7 +28,8 @@
 /*
  * Signalling areas
  */
-#define S_PAGING 0x0001
+#define S_PAGING	0x0001
+#define S_SMS		0x0002
 
 
 struct signal_data {
@@ -46,6 +47,12 @@
 	struct gsm_lchan *lchan;
 };
 
+struct sms_signal_data {
+	struct signal_data data;
+
+	struct sms_submit *sms;
+};
+
 
 /* Management */
 void register_signal_handler(int areas, int (*sig)(struct signal_data *, void *data), void *data);