diff --git a/lib/dns/zone.c b/lib/dns/zone.c
index 4f98f38a6a..c9bca4bd94 100644
--- a/lib/dns/zone.c
+++ b/lib/dns/zone.c
@@ -11063,6 +11063,7 @@ zone_maintenance(dns_zone_t *zone) {
 	isc_time_t now;
 	isc_result_t result;
 	bool dumping, load_pending, viewok;
+	bool need_notify;
 
 	REQUIRE(DNS_ZONE_VALID(zone));
 	ENTER;
@@ -11147,11 +11148,15 @@ zone_maintenance(dns_zone_t *zone) {
 	 * Secondaries send notifies before backing up to disk,
 	 * primaries after.
 	 */
-	if ((zone->type == dns_zone_slave || zone->type == dns_zone_mirror) &&
-	    (DNS_ZONE_FLAG(zone, DNS_ZONEFLG_NEEDNOTIFY) ||
-	     DNS_ZONE_FLAG(zone, DNS_ZONEFLG_NEEDSTARTUPNOTIFY)) &&
-	    isc_time_compare(&now, &zone->notifytime) >= 0)
-	{
+	LOCK_ZONE(zone);
+	need_notify = (zone->type == dns_zone_slave ||
+		       zone->type == dns_zone_mirror) &&
+		      (DNS_ZONE_FLAG(zone, DNS_ZONEFLG_NEEDNOTIFY) ||
+		       DNS_ZONE_FLAG(zone, DNS_ZONEFLG_NEEDSTARTUPNOTIFY)) &&
+		      (isc_time_compare(&now, &zone->notifytime) >= 0);
+	UNLOCK_ZONE(zone);
+
+	if (need_notify) {
 		zone_notify(zone, &now);
 	}