diff --git a/libpri.h b/libpri.h
index 3fe9135..c042d34 100755
--- a/libpri.h
+++ b/libpri.h
@@ -337,6 +337,7 @@ typedef struct pri_event_restart_ack {
 	int channel;
 } pri_event_restart_ack;
 
+#define PRI_PROGRESS_CAUSE
 typedef struct pri_event_proceeding {
 	int e;
 	int channel;