diff --git a/bin/named/server.c b/bin/named/server.c
index f27d4c3eda..677efed0d3 100644
--- a/bin/named/server.c
+++ b/bin/named/server.c
@@ -2689,6 +2689,8 @@ catz_addmodzone_taskaction(isc_task_t *task, isc_event_t *event0) {
 				      isc_result_totext(result), nameb);
 			goto cleanup;
 		} else {
+			dns_catz_zone_t *parentcatz;
+
 			if (!dns_zone_getadded(zone)) {
 				isc_log_write(
 					named_g_lctx, NAMED_LOGCATEGORY_GENERAL,
@@ -2700,7 +2702,20 @@ catz_addmodzone_taskaction(isc_task_t *task, isc_event_t *event0) {
 					nameb);
 				goto cleanup;
 			}
-			if (dns_zone_get_parentcatz(zone) != ev->origin) {
+
+			parentcatz = dns_zone_get_parentcatz(zone);
+
+			if (parentcatz == NULL) {
+				isc_log_write(
+					named_g_lctx, NAMED_LOGCATEGORY_GENERAL,
+					NAMED_LOGMODULE_SERVER, ISC_LOG_WARNING,
+					"catz: catz_addmodzone_taskaction: "
+					"zone '%s' exists and is not added by "
+					"a catalog zone, so won't be modified",
+					nameb);
+				goto cleanup;
+			}
+			if (parentcatz != ev->origin) {
 				isc_log_write(
 					named_g_lctx, NAMED_LOGCATEGORY_GENERAL,
 					NAMED_LOGMODULE_SERVER, ISC_LOG_WARNING,
@@ -2710,6 +2725,7 @@ catz_addmodzone_taskaction(isc_task_t *task, isc_event_t *event0) {
 					nameb);
 				goto cleanup;
 			}
+
 			dns_zone_detach(&zone);
 		}
 	} else {