diff --git a/hmp.h b/hmp.h
index 2b0c1e4..9182622 100644
--- a/hmp.h
+++ b/hmp.h
@@ -47,5 +47,6 @@
 void hmp_block_resize(Monitor *mon, const QDict *qdict);
 void hmp_snapshot_blkdev(Monitor *mon, const QDict *qdict);
 void hmp_migrate_cancel(Monitor *mon, const QDict *qdict);
+void hmp_migrate_set_downtime(Monitor *mon, const QDict *qdict);
 
 #endif