diff --git a/servers/slapd/back-monitor/back-monitor.h b/servers/slapd/back-monitor/back-monitor.h
index d98b946a77..49618958cb 100644
--- a/servers/slapd/back-monitor/back-monitor.h
+++ b/servers/slapd/back-monitor/back-monitor.h
@@ -268,6 +268,8 @@ typedef struct monitor_subsys_t {
 				struct berval *ndn, Entry *, Entry ** );
 	/* modify entry and subentries */
 	int		( *mss_modify )( Operation *, SlapReply *, Entry * );
+
+	void		*mss_private;
 } monitor_subsys_t;
 
 extern BackendDB *be_monitor;