diff --git a/x-pack/legacy/plugins/watcher/server/np_ready/lib/is_es_error_factory/index.ts b/x-pack/legacy/plugins/watcher/server/np_ready/lib/is_es_error/index.ts
similarity index 80%
rename from x-pack/legacy/plugins/watcher/server/np_ready/lib/is_es_error_factory/index.ts
rename to x-pack/legacy/plugins/watcher/server/np_ready/lib/is_es_error/index.ts
index 441648a8701e0..a9a3c61472d8c 100644
--- a/x-pack/legacy/plugins/watcher/server/np_ready/lib/is_es_error_factory/index.ts
+++ b/x-pack/legacy/plugins/watcher/server/np_ready/lib/is_es_error/index.ts
@@ -4,4 +4,4 @@
  * you may not use this file except in compliance with the Elastic License.
  */
 
-export { isEsErrorFactory } from './is_es_error_factory';
+export { isEsError } from './is_es_error';
diff --git a/x-pack/legacy/plugins/watcher/server/np_ready/lib/is_es_error/is_es_error.ts b/x-pack/legacy/plugins/watcher/server/np_ready/lib/is_es_error/is_es_error.ts
new file mode 100644
index 0000000000000..4137293cf39c0
--- /dev/null
+++ b/x-pack/legacy/plugins/watcher/server/np_ready/lib/is_es_error/is_es_error.ts
@@ -0,0 +1,13 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License;
+ * you may not use this file except in compliance with the Elastic License.
+ */
+
+import * as legacyElasticsearch from 'elasticsearch';
+
+const esErrorsParent = legacyElasticsearch.errors._Abstract;
+
+export function isEsError(err: Error) {
+  return err instanceof esErrorsParent;
+}
diff --git a/x-pack/legacy/plugins/watcher/server/np_ready/lib/is_es_error_factory/__tests__/is_es_error_factory.js b/x-pack/legacy/plugins/watcher/server/np_ready/lib/is_es_error_factory/__tests__/is_es_error_factory.js
deleted file mode 100644
index 76fdf7b36c3d0..0000000000000
--- a/x-pack/legacy/plugins/watcher/server/np_ready/lib/is_es_error_factory/__tests__/is_es_error_factory.js
+++ /dev/null
@@ -1,48 +0,0 @@
-/*
- * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
- * or more contributor license agreements. Licensed under the Elastic License;
- * you may not use this file except in compliance with the Elastic License.
- */
-
-import expect from '@kbn/expect';
-import { isEsErrorFactory } from '../is_es_error_factory';
-import { set } from 'lodash';
-
-class MockAbstractEsError {}
-
-describe('is_es_error_factory', () => {
-
-  let mockServer;
-  let isEsError;
-
-  beforeEach(() => {
-    const mockEsErrors = {
-      _Abstract: MockAbstractEsError
-    };
-    mockServer = {};
-    set(mockServer, 'plugins.elasticsearch.getCluster', () => ({ errors: mockEsErrors }));
-
-    isEsError = isEsErrorFactory(mockServer);
-  });
-
-  describe('#isEsErrorFactory', () => {
-
-    it('should return a function', () => {
-      expect(isEsError).to.be.a(Function);
-    });
-
-    describe('returned function', () => {
-
-      it('should return true if passed-in err is a known esError', () => {
-        const knownEsError = new MockAbstractEsError();
-        expect(isEsError(knownEsError)).to.be(true);
-      });
-
-      it('should return false if passed-in err is not a known esError', () => {
-        const unknownEsError = {};
-        expect(isEsError(unknownEsError)).to.be(false);
-
-      });
-    });
-  });
-});
diff --git a/x-pack/legacy/plugins/watcher/server/np_ready/lib/is_es_error_factory/is_es_error_factory.ts b/x-pack/legacy/plugins/watcher/server/np_ready/lib/is_es_error_factory/is_es_error_factory.ts
deleted file mode 100644
index c79eb5866803f..0000000000000
--- a/x-pack/legacy/plugins/watcher/server/np_ready/lib/is_es_error_factory/is_es_error_factory.ts
+++ /dev/null
@@ -1,19 +0,0 @@
-/*
- * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
- * or more contributor license agreements. Licensed under the Elastic License;
- * you may not use this file except in compliance with the Elastic License.
- */
-
-import { memoize } from 'lodash';
-import { ServerShim } from '../../types';
-
-const esErrorsFactory = memoize((server: ServerShim) => {
-  return (server.plugins.elasticsearch.getCluster('admin') as any).errors;
-});
-
-export function isEsErrorFactory(server: ServerShim) {
-  const esErrors = esErrorsFactory(server);
-  return function isEsError(err: Error) {
-    return err instanceof esErrors._Abstract;
-  };
-}
diff --git a/x-pack/legacy/plugins/watcher/server/np_ready/routes/api/indices/register_get_route.ts b/x-pack/legacy/plugins/watcher/server/np_ready/routes/api/indices/register_get_route.ts
index 31bc4c785e300..fecc5e016de5c 100644
--- a/x-pack/legacy/plugins/watcher/server/np_ready/routes/api/indices/register_get_route.ts
+++ b/x-pack/legacy/plugins/watcher/server/np_ready/routes/api/indices/register_get_route.ts
@@ -7,7 +7,7 @@
 import { RequestHandler } from 'src/core/server';
 import { reduce, size } from 'lodash';
 import { callWithRequestFactory } from '../../../lib/call_with_request_factory';
-import { isEsErrorFactory } from '../../../lib/is_es_error_factory';
+import { isEsError } from '../../../lib/is_es_error';
 import { licensePreRoutingFactory } from '../../../lib/license_pre_routing_factory';
 import { RouteDependencies, ServerShim } from '../../../types';
 
@@ -61,7 +61,6 @@ function getIndices(callWithRequest: any, pattern: string, limit = 10) {
 }
 
 export function registerGetRoute(deps: RouteDependencies, legacy: ServerShim) {
-  const isEsError = isEsErrorFactory(legacy);
   const handler: RequestHandler<any, any, any> = async (ctx, request, response) => {
     const callWithRequest = callWithRequestFactory(deps.elasticsearchService, request);
     const { pattern } = request.body;
diff --git a/x-pack/legacy/plugins/watcher/server/np_ready/routes/api/register_list_fields_route.ts b/x-pack/legacy/plugins/watcher/server/np_ready/routes/api/register_list_fields_route.ts
index 3ec218f25ffa6..75622ce12adb3 100644
--- a/x-pack/legacy/plugins/watcher/server/np_ready/routes/api/register_list_fields_route.ts
+++ b/x-pack/legacy/plugins/watcher/server/np_ready/routes/api/register_list_fields_route.ts
@@ -6,7 +6,7 @@
 
 import { RequestHandler } from 'src/core/server';
 import { callWithRequestFactory } from '../../lib/call_with_request_factory';
-import { isEsErrorFactory } from '../../lib/is_es_error_factory';
+import { isEsError } from '../../lib/is_es_error';
 import { licensePreRoutingFactory } from '../../lib/license_pre_routing_factory';
 // @ts-ignore
 import { Fields } from '../../models/fields';
@@ -25,8 +25,6 @@ function fetchFields(callWithRequest: any, indexes: string[]) {
 }
 
 export function registerListFieldsRoute(deps: RouteDependencies, legacy: ServerShim) {
-  const isEsError = isEsErrorFactory(legacy);
-
   const handler: RequestHandler<any, any, any> = async (ctx, request, response) => {
     const callWithRequest = callWithRequestFactory(deps.elasticsearchService, request);
     const { indexes } = request.body;
diff --git a/x-pack/legacy/plugins/watcher/server/np_ready/routes/api/register_load_history_route.ts b/x-pack/legacy/plugins/watcher/server/np_ready/routes/api/register_load_history_route.ts
index 869293334478e..d62e4f48c5629 100644
--- a/x-pack/legacy/plugins/watcher/server/np_ready/routes/api/register_load_history_route.ts
+++ b/x-pack/legacy/plugins/watcher/server/np_ready/routes/api/register_load_history_route.ts
@@ -8,7 +8,7 @@ import { schema } from '@kbn/config-schema';
 import { get } from 'lodash';
 import { RequestHandler } from 'src/core/server';
 import { callWithRequestFactory } from '../../lib/call_with_request_factory';
-import { isEsErrorFactory } from '../../lib/is_es_error_factory';
+import { isEsError } from '../../lib/is_es_error';
 import { INDEX_NAMES } from '../../../../common/constants';
 import { licensePreRoutingFactory } from '../../lib/license_pre_routing_factory';
 import { RouteDependencies, ServerShim } from '../../types';
@@ -29,7 +29,6 @@ function fetchHistoryItem(callWithRequest: any, watchHistoryItemId: string) {
 }
 
 export function registerLoadHistoryRoute(deps: RouteDependencies, legacy: ServerShim) {
-  const isEsError = isEsErrorFactory(legacy);
   const handler: RequestHandler<any, any, any> = async (ctx, request, response) => {
     const callWithRequest = callWithRequestFactory(deps.elasticsearchService, request);
     const id = request.params.id;
diff --git a/x-pack/legacy/plugins/watcher/server/np_ready/routes/api/settings/register_load_route.ts b/x-pack/legacy/plugins/watcher/server/np_ready/routes/api/settings/register_load_route.ts
index 5c8818b43f9a4..710d079d810da 100644
--- a/x-pack/legacy/plugins/watcher/server/np_ready/routes/api/settings/register_load_route.ts
+++ b/x-pack/legacy/plugins/watcher/server/np_ready/routes/api/settings/register_load_route.ts
@@ -5,7 +5,7 @@
  */
 
 import { IClusterClient, RequestHandler } from 'src/core/server';
-import { isEsErrorFactory } from '../../../lib/is_es_error_factory';
+import { isEsError } from '../../../lib/is_es_error';
 import { licensePreRoutingFactory } from '../../../lib/license_pre_routing_factory';
 // @ts-ignore
 import { Settings } from '../../../models/settings';
@@ -19,7 +19,6 @@ function fetchClusterSettings(client: IClusterClient) {
 }
 
 export function registerLoadRoute(deps: RouteDependencies, legacy: ServerShim) {
-  const isEsError = isEsErrorFactory(legacy);
   const handler: RequestHandler<any, any, any> = async (ctx, request, response) => {
     try {
       const settings = await fetchClusterSettings(deps.elasticsearch);
diff --git a/x-pack/legacy/plugins/watcher/server/np_ready/routes/api/watch/action/register_acknowledge_route.ts b/x-pack/legacy/plugins/watcher/server/np_ready/routes/api/watch/action/register_acknowledge_route.ts
index 0be94dda47cb3..d0cc0a27e87ff 100644
--- a/x-pack/legacy/plugins/watcher/server/np_ready/routes/api/watch/action/register_acknowledge_route.ts
+++ b/x-pack/legacy/plugins/watcher/server/np_ready/routes/api/watch/action/register_acknowledge_route.ts
@@ -8,7 +8,7 @@ import { schema } from '@kbn/config-schema';
 import { get } from 'lodash';
 import { RequestHandler } from 'src/core/server';
 import { callWithRequestFactory } from '../../../../lib/call_with_request_factory';
-import { isEsErrorFactory } from '../../../../lib/is_es_error_factory';
+import { isEsError } from '../../../../lib/is_es_error';
 import { licensePreRoutingFactory } from '../../../../lib/license_pre_routing_factory';
 // @ts-ignore
 import { WatchStatus } from '../../../../models/watch_status';
@@ -22,7 +22,6 @@ function acknowledgeAction(callWithRequest: any, watchId: string, actionId: stri
 }
 
 export function registerAcknowledgeRoute(deps: RouteDependencies, legacy: ServerShim) {
-  const isEsError = isEsErrorFactory(legacy);
   const handler: RequestHandler<any, any, any> = async (ctx, request, response) => {
     const callWithRequest = callWithRequestFactory(deps.elasticsearchService, request);
     const { watchId, actionId } = request.params;
diff --git a/x-pack/legacy/plugins/watcher/server/np_ready/routes/api/watch/register_activate_route.ts b/x-pack/legacy/plugins/watcher/server/np_ready/routes/api/watch/register_activate_route.ts
index 3f7d132b7d352..28c482124aaee 100644
--- a/x-pack/legacy/plugins/watcher/server/np_ready/routes/api/watch/register_activate_route.ts
+++ b/x-pack/legacy/plugins/watcher/server/np_ready/routes/api/watch/register_activate_route.ts
@@ -8,7 +8,7 @@ import { schema } from '@kbn/config-schema';
 import { RequestHandler } from 'src/core/server';
 import { get } from 'lodash';
 import { callWithRequestFactory } from '../../../lib/call_with_request_factory';
-import { isEsErrorFactory } from '../../../lib/is_es_error_factory';
+import { isEsError } from '../../../lib/is_es_error';
 import { licensePreRoutingFactory } from '../../../lib/license_pre_routing_factory';
 import { RouteDependencies, ServerShim } from '../../../types';
 // @ts-ignore
@@ -21,7 +21,6 @@ function activateWatch(callWithRequest: any, watchId: string) {
 }
 
 export function registerActivateRoute(deps: RouteDependencies, legacy: ServerShim) {
-  const isEsError = isEsErrorFactory(legacy);
   const handler: RequestHandler<any, any, any> = async (ctx, request, response) => {
     const callWithRequest = callWithRequestFactory(deps.elasticsearchService, request);
 
diff --git a/x-pack/legacy/plugins/watcher/server/np_ready/routes/api/watch/register_deactivate_route.ts b/x-pack/legacy/plugins/watcher/server/np_ready/routes/api/watch/register_deactivate_route.ts
index 9108190489fe5..ac87066379a20 100644
--- a/x-pack/legacy/plugins/watcher/server/np_ready/routes/api/watch/register_deactivate_route.ts
+++ b/x-pack/legacy/plugins/watcher/server/np_ready/routes/api/watch/register_deactivate_route.ts
@@ -7,7 +7,7 @@ import { schema } from '@kbn/config-schema';
 import { RequestHandler } from 'src/core/server';
 import { get } from 'lodash';
 import { callWithRequestFactory } from '../../../lib/call_with_request_factory';
-import { isEsErrorFactory } from '../../../lib/is_es_error_factory';
+import { isEsError } from '../../../lib/is_es_error';
 import { licensePreRoutingFactory } from '../../../lib/license_pre_routing_factory';
 import { RouteDependencies, ServerShim } from '../../../types';
 // @ts-ignore
@@ -20,7 +20,6 @@ function deactivateWatch(callWithRequest: any, watchId: string) {
 }
 
 export function registerDeactivateRoute(deps: RouteDependencies, legacy: ServerShim) {
-  const isEsError = isEsErrorFactory(legacy);
   const handler: RequestHandler<any, any, any> = async (ctx, request, response) => {
     const callWithRequest = callWithRequestFactory(deps.elasticsearchService, request);
 
diff --git a/x-pack/legacy/plugins/watcher/server/np_ready/routes/api/watch/register_delete_route.ts b/x-pack/legacy/plugins/watcher/server/np_ready/routes/api/watch/register_delete_route.ts
index 5e974d48dff0e..3402cc283dba0 100644
--- a/x-pack/legacy/plugins/watcher/server/np_ready/routes/api/watch/register_delete_route.ts
+++ b/x-pack/legacy/plugins/watcher/server/np_ready/routes/api/watch/register_delete_route.ts
@@ -7,7 +7,7 @@
 import { schema } from '@kbn/config-schema';
 import { RequestHandler } from 'src/core/server';
 import { callWithRequestFactory } from '../../../lib/call_with_request_factory';
-import { isEsErrorFactory } from '../../../lib/is_es_error_factory';
+import { isEsError } from '../../../lib/is_es_error';
 import { licensePreRoutingFactory } from '../../../lib/license_pre_routing_factory';
 import { RouteDependencies, ServerShim } from '../../../types';
 
@@ -18,7 +18,6 @@ function deleteWatch(callWithRequest: any, watchId: string) {
 }
 
 export function registerDeleteRoute(deps: RouteDependencies, legacy: ServerShim) {
-  const isEsError = isEsErrorFactory(legacy);
   const handler: RequestHandler<any, any, any> = async (ctx, request, response) => {
     const callWithRequest = callWithRequestFactory(deps.elasticsearchService, request);
 
diff --git a/x-pack/legacy/plugins/watcher/server/np_ready/routes/api/watch/register_execute_route.ts b/x-pack/legacy/plugins/watcher/server/np_ready/routes/api/watch/register_execute_route.ts
index 06da7ad8341d3..f3bce228653fe 100644
--- a/x-pack/legacy/plugins/watcher/server/np_ready/routes/api/watch/register_execute_route.ts
+++ b/x-pack/legacy/plugins/watcher/server/np_ready/routes/api/watch/register_execute_route.ts
@@ -8,7 +8,7 @@ import { schema } from '@kbn/config-schema';
 import { RequestHandler } from 'src/core/server';
 import { get } from 'lodash';
 import { callWithRequestFactory } from '../../../lib/call_with_request_factory';
-import { isEsErrorFactory } from '../../../lib/is_es_error_factory';
+import { isEsError } from '../../../lib/is_es_error';
 import { licensePreRoutingFactory } from '../../../lib/license_pre_routing_factory';
 
 import { RouteDependencies, ServerShim } from '../../../types';
@@ -29,7 +29,6 @@ function executeWatch(callWithRequest: any, executeDetails: any, watchJson: any)
 }
 
 export function registerExecuteRoute(deps: RouteDependencies, legacy: ServerShim) {
-  const isEsError = isEsErrorFactory(legacy);
   const handler: RequestHandler<any, any, any> = async (ctx, request, response) => {
     const callWithRequest = callWithRequestFactory(deps.elasticsearchService, request);
     const executeDetails = ExecuteDetails.fromDownstreamJson(request.body.executeDetails);
diff --git a/x-pack/legacy/plugins/watcher/server/np_ready/routes/api/watch/register_history_route.ts b/x-pack/legacy/plugins/watcher/server/np_ready/routes/api/watch/register_history_route.ts
index 49d83485c9ec9..e236d7dd642a3 100644
--- a/x-pack/legacy/plugins/watcher/server/np_ready/routes/api/watch/register_history_route.ts
+++ b/x-pack/legacy/plugins/watcher/server/np_ready/routes/api/watch/register_history_route.ts
@@ -10,7 +10,7 @@ import { get } from 'lodash';
 import { callWithRequestFactory } from '../../../lib/call_with_request_factory';
 import { fetchAllFromScroll } from '../../../lib/fetch_all_from_scroll';
 import { INDEX_NAMES, ES_SCROLL_SETTINGS } from '../../../../../common/constants';
-import { isEsErrorFactory } from '../../../lib/is_es_error_factory';
+import { isEsError } from '../../../lib/is_es_error';
 import { licensePreRoutingFactory } from '../../../lib/license_pre_routing_factory';
 import { RouteDependencies, ServerShim } from '../../../types';
 // @ts-ignore
@@ -43,7 +43,6 @@ function fetchHistoryItems(callWithRequest: any, watchId: any, startTime: any) {
 }
 
 export function registerHistoryRoute(deps: RouteDependencies, legacy: ServerShim) {
-  const isEsError = isEsErrorFactory(legacy);
   const handler: RequestHandler<any, any, any> = async (ctx, request, response) => {
     const callWithRequest = callWithRequestFactory(deps.elasticsearchService, request);
     const { watchId } = request.params;
diff --git a/x-pack/legacy/plugins/watcher/server/np_ready/routes/api/watch/register_load_route.ts b/x-pack/legacy/plugins/watcher/server/np_ready/routes/api/watch/register_load_route.ts
index 17f59300da73f..7311ad08f73a6 100644
--- a/x-pack/legacy/plugins/watcher/server/np_ready/routes/api/watch/register_load_route.ts
+++ b/x-pack/legacy/plugins/watcher/server/np_ready/routes/api/watch/register_load_route.ts
@@ -8,7 +8,7 @@ import { schema } from '@kbn/config-schema';
 import { RequestHandler } from 'src/core/server';
 import { get } from 'lodash';
 import { callWithRequestFactory } from '../../../lib/call_with_request_factory';
-import { isEsErrorFactory } from '../../../lib/is_es_error_factory';
+import { isEsError } from '../../../lib/is_es_error';
 import { licensePreRoutingFactory } from '../../../lib/license_pre_routing_factory';
 // @ts-ignore
 import { Watch } from '../../../models/watch';
@@ -21,7 +21,6 @@ function fetchWatch(callWithRequest: any, watchId: string) {
 }
 
 export function registerLoadRoute(deps: RouteDependencies, legacy: ServerShim) {
-  const isEsError = isEsErrorFactory(legacy);
   const handler: RequestHandler<any, any, any> = async (ctx, request, response) => {
     const callWithRequest = callWithRequestFactory(deps.elasticsearchService, request);
 
diff --git a/x-pack/legacy/plugins/watcher/server/np_ready/routes/api/watch/register_save_route.ts b/x-pack/legacy/plugins/watcher/server/np_ready/routes/api/watch/register_save_route.ts
index f16bd233040bd..5d22392d49ed8 100644
--- a/x-pack/legacy/plugins/watcher/server/np_ready/routes/api/watch/register_save_route.ts
+++ b/x-pack/legacy/plugins/watcher/server/np_ready/routes/api/watch/register_save_route.ts
@@ -13,7 +13,7 @@ import {
   serializeThresholdWatch,
 } from '../../../../../common/lib/serialization';
 import { callWithRequestFactory } from '../../../lib/call_with_request_factory';
-import { isEsErrorFactory } from '../../../lib/is_es_error_factory';
+import { isEsError } from '../../../lib/is_es_error';
 import { licensePreRoutingFactory } from '../../../lib/license_pre_routing_factory';
 import { RouteDependencies, ServerShim } from '../../../types';
 
@@ -31,7 +31,6 @@ function saveWatch(callWithRequest: any, id: string, body: any) {
 }
 
 export function registerSaveRoute(deps: RouteDependencies, legacy: ServerShim) {
-  const isEsError = isEsErrorFactory(legacy);
   const handler: RequestHandler<any, any, any> = async (ctx, request, response) => {
     const callWithRequest = callWithRequestFactory(deps.elasticsearchService, request);
     const { id } = request.params;
diff --git a/x-pack/legacy/plugins/watcher/server/np_ready/routes/api/watch/register_visualize_route.ts b/x-pack/legacy/plugins/watcher/server/np_ready/routes/api/watch/register_visualize_route.ts
index d7f4158a4eebc..d07a264b0b2b1 100644
--- a/x-pack/legacy/plugins/watcher/server/np_ready/routes/api/watch/register_visualize_route.ts
+++ b/x-pack/legacy/plugins/watcher/server/np_ready/routes/api/watch/register_visualize_route.ts
@@ -7,7 +7,7 @@
 import { schema } from '@kbn/config-schema';
 import { RequestHandler } from 'src/core/server';
 import { callWithRequestFactory } from '../../../lib/call_with_request_factory';
-import { isEsErrorFactory } from '../../../lib/is_es_error_factory';
+import { isEsError } from '../../../lib/is_es_error';
 import { licensePreRoutingFactory } from '../../../lib/license_pre_routing_factory';
 import { RouteDependencies, ServerShim } from '../../../types';
 
@@ -29,7 +29,6 @@ function fetchVisualizeData(callWithRequest: any, index: any, body: any) {
 }
 
 export function registerVisualizeRoute(deps: RouteDependencies, legacy: ServerShim) {
-  const isEsError = isEsErrorFactory(legacy);
   const handler: RequestHandler<any, any, any> = async (ctx, request, response) => {
     const callWithRequest = callWithRequestFactory(deps.elasticsearchService, request);
     const watch = Watch.fromDownstreamJson(request.body.watch);
diff --git a/x-pack/legacy/plugins/watcher/server/np_ready/routes/api/watches/register_list_route.ts b/x-pack/legacy/plugins/watcher/server/np_ready/routes/api/watches/register_list_route.ts
index db90b3f5b26ff..b94c29e0f9892 100644
--- a/x-pack/legacy/plugins/watcher/server/np_ready/routes/api/watches/register_list_route.ts
+++ b/x-pack/legacy/plugins/watcher/server/np_ready/routes/api/watches/register_list_route.ts
@@ -9,7 +9,7 @@ import { get } from 'lodash';
 import { callWithRequestFactory } from '../../../lib/call_with_request_factory';
 import { fetchAllFromScroll } from '../../../lib/fetch_all_from_scroll';
 import { INDEX_NAMES, ES_SCROLL_SETTINGS } from '../../../../../common/constants';
-import { isEsErrorFactory } from '../../../lib/is_es_error_factory';
+import { isEsError } from '../../../lib/is_es_error';
 import { licensePreRoutingFactory } from '../../../lib/license_pre_routing_factory';
 import { RouteDependencies, ServerShim } from '../../../types';
 // @ts-ignore
@@ -31,7 +31,6 @@ function fetchWatches(callWithRequest: any) {
 }
 
 export function registerListRoute(deps: RouteDependencies, legacy: ServerShim) {
-  const isEsError = isEsErrorFactory(legacy);
   const handler: RequestHandler<any, any, any> = async (ctx, request, response) => {
     const callWithRequest = callWithRequestFactory(deps.elasticsearchService, request);