diff --git a/x-pack/plugins/monitoring/common/types/es.ts b/x-pack/plugins/monitoring/common/types/es.ts
index a9d020813ce84..a01e1c383a8e6 100644
--- a/x-pack/plugins/monitoring/common/types/es.ts
+++ b/x-pack/plugins/monitoring/common/types/es.ts
@@ -156,7 +156,7 @@ export interface ElasticsearchLegacySource {
           heap_max_in_bytes?: number;
         };
       };
-      fs: {
+      fs?: {
         available_in_bytes?: number;
         total_in_bytes?: number;
       };
@@ -497,7 +497,7 @@ export interface ElasticsearchMetricbeatSource {
         };
         nodes?: {
           versions?: string[];
-          count?: number;
+          count?: number | {};
           jvm?: {
             max_uptime?: {
               ms?: number;
diff --git a/x-pack/plugins/monitoring/server/lib/standalone_clusters/get_standalone_cluster_definition.js b/x-pack/plugins/monitoring/server/lib/standalone_clusters/get_standalone_cluster_definition.ts
similarity index 84%
rename from x-pack/plugins/monitoring/server/lib/standalone_clusters/get_standalone_cluster_definition.js
rename to x-pack/plugins/monitoring/server/lib/standalone_clusters/get_standalone_cluster_definition.ts
index ccbc6ccaa78aa..7529b5020d1ff 100644
--- a/x-pack/plugins/monitoring/server/lib/standalone_clusters/get_standalone_cluster_definition.js
+++ b/x-pack/plugins/monitoring/server/lib/standalone_clusters/get_standalone_cluster_definition.ts
@@ -6,8 +6,9 @@
  */
 
 import { STANDALONE_CLUSTER_CLUSTER_UUID } from '../../../common/constants';
+import { Cluster } from '../../types';
 
-export const getStandaloneClusterDefinition = () => {
+export const getStandaloneClusterDefinition: () => Cluster = () => {
   return {
     cluster_uuid: STANDALONE_CLUSTER_CLUSTER_UUID,
     license: {},
@@ -28,5 +29,5 @@ export const getStandaloneClusterDefinition = () => {
         },
       },
     },
-  };
+  } as Cluster;
 };
diff --git a/x-pack/plugins/monitoring/server/lib/standalone_clusters/has_standalone_clusters.js b/x-pack/plugins/monitoring/server/lib/standalone_clusters/has_standalone_clusters.ts
similarity index 87%
rename from x-pack/plugins/monitoring/server/lib/standalone_clusters/has_standalone_clusters.js
rename to x-pack/plugins/monitoring/server/lib/standalone_clusters/has_standalone_clusters.ts
index 938610e51693e..42ac8b89eaf37 100644
--- a/x-pack/plugins/monitoring/server/lib/standalone_clusters/has_standalone_clusters.js
+++ b/x-pack/plugins/monitoring/server/lib/standalone_clusters/has_standalone_clusters.ts
@@ -7,15 +7,16 @@
 
 import moment from 'moment';
 import { get } from 'lodash';
+import { LegacyRequest } from '../../types';
 import { standaloneClusterFilter } from './';
 
-export async function hasStandaloneClusters(req, indexPatterns) {
+export async function hasStandaloneClusters(req: LegacyRequest, indexPatterns: string[]) {
   const indexPatternList = indexPatterns.reduce((list, patterns) => {
     list.push(...patterns.split(','));
     return list;
-  }, []);
+  }, [] as string[]);
 
-  const filters = [
+  const filters: any[] = [
     standaloneClusterFilter,
     {
       bool: {
@@ -39,7 +40,7 @@ export async function hasStandaloneClusters(req, indexPatterns) {
     const start = req.payload.timeRange.min;
     const end = req.payload.timeRange.max;
 
-    const timeRangeFilter = {
+    const timeRangeFilter: { range: { timestamp: Record<string, any> } } = {
       range: {
         timestamp: {
           format: 'epoch_millis',