diff --git a/plugins/catalog-backend/api-report.md b/plugins/catalog-backend/api-report.md
index f6e864221c..01a824d049 100644
--- a/plugins/catalog-backend/api-report.md
+++ b/plugins/catalog-backend/api-report.md
@@ -7,6 +7,7 @@
 
 import { Account } from 'aws-sdk/clients/organizations';
 import { BitbucketIntegration } from '@backstage/integration';
+import { CatalogApi } from '@backstage/catalog-client';
 import { CatalogEntitiesRequest } from '@backstage/catalog-client';
 import { Config } from '@backstage/config';
 import { DocumentCollator } from '@backstage/search-common';
@@ -567,10 +568,12 @@ export class DefaultCatalogCollator implements DocumentCollator {
     discovery,
     locationTemplate,
     filter,
+    catalogClient,
   }: {
     discovery: PluginEndpointDiscovery;
     locationTemplate?: string;
     filter?: CatalogEntitiesRequest['filter'];
+    catalogClient?: CatalogApi;
   });
   // (undocumented)
   protected applyArgsToFormat(
@@ -578,13 +581,15 @@ export class DefaultCatalogCollator implements DocumentCollator {
     args: Record<string, string>,
   ): string;
   // (undocumented)
+  protected readonly catalogClient: CatalogApi;
+  // (undocumented)
   protected discovery: PluginEndpointDiscovery;
   // Warning: (ae-forgotten-export) The symbol "CatalogEntityDocument" needs to be exported by the entry point index.d.ts
   //
   // (undocumented)
   execute(): Promise<CatalogEntityDocument[]>;
   // (undocumented)
-  protected filterUrl?: string;
+  protected filter?: CatalogEntitiesRequest['filter'];
   // (undocumented)
   static fromConfig(
     _config: Config,
diff --git a/plugins/catalog-backend/src/search/DefaultCatalogCollator.test.ts b/plugins/catalog-backend/src/search/DefaultCatalogCollator.test.ts
index f1b7cfe862..bb556fc49f 100644
--- a/plugins/catalog-backend/src/search/DefaultCatalogCollator.test.ts
+++ b/plugins/catalog-backend/src/search/DefaultCatalogCollator.test.ts
@@ -16,10 +16,7 @@
 
 import { PluginEndpointDiscovery } from '@backstage/backend-common';
 import { Entity } from '@backstage/catalog-model';
-import {
-  DefaultCatalogCollator,
-  mapFilterToQueryString,
-} from './DefaultCatalogCollator';
+import { DefaultCatalogCollator } from './DefaultCatalogCollator';
 import { setupServer } from 'msw/node';
 import { rest } from 'msw';
 import { ConfigReader } from '@backstage/config';
@@ -59,7 +56,7 @@ describe('DefaultCatalogCollator', () => {
       rest.get('http://localhost:7000/entities', (req, res, ctx) => {
         if (req.url.searchParams.has('filter')) {
           const filter = req.url.searchParams.get('filter');
-          if (filter === 'kind=Foo,Bar') {
+          if (filter === 'kind=Foo,kind=Bar') {
             // When filtering on the 'Foo,Bar' kinds we simply return no items, to simulate a filter
             return res(ctx.json([]));
           }
@@ -120,23 +117,4 @@ describe('DefaultCatalogCollator', () => {
     // The simulated 'Foo,Bar' filter should return in an empty list
     expect(documents).toHaveLength(0);
   });
-
-  it('can map filters to query strings', () => {
-    expect(
-      mapFilterToQueryString({
-        a: 'Foo',
-      }),
-    ).toEqual('?filter=a=Foo');
-    expect(
-      mapFilterToQueryString({
-        a: ['Foo', 'Bar'],
-      }),
-    ).toEqual('?filter=a=Foo,Bar');
-    expect(
-      mapFilterToQueryString({
-        a: ['Foo', 'Bar'],
-        b: ['Quu', 'Qux'],
-      }),
-    ).toEqual('?filter=a=Foo,Bar,b=Quu,Qux');
-  });
 });
diff --git a/plugins/catalog-backend/src/search/DefaultCatalogCollator.ts b/plugins/catalog-backend/src/search/DefaultCatalogCollator.ts
index b372350a08..6292b2a833 100644
--- a/plugins/catalog-backend/src/search/DefaultCatalogCollator.ts
+++ b/plugins/catalog-backend/src/search/DefaultCatalogCollator.ts
@@ -17,9 +17,12 @@
 import { PluginEndpointDiscovery } from '@backstage/backend-common';
 import { Entity } from '@backstage/catalog-model';
 import { IndexableDocument, DocumentCollator } from '@backstage/search-common';
-import fetch from 'cross-fetch';
 import { Config } from '@backstage/config';
-import { CatalogEntitiesRequest } from '@backstage/catalog-client';
+import {
+  CatalogApi,
+  CatalogClient,
+  CatalogEntitiesRequest,
+} from '@backstage/catalog-client';
 
 export interface CatalogEntityDocument extends IndexableDocument {
   componentType: string;
@@ -32,7 +35,8 @@ export interface CatalogEntityDocument extends IndexableDocument {
 export class DefaultCatalogCollator implements DocumentCollator {
   protected discovery: PluginEndpointDiscovery;
   protected locationTemplate: string;
-  protected filterUrl?: string;
+  protected filter?: CatalogEntitiesRequest['filter'];
+  protected readonly catalogClient: CatalogApi;
   public readonly type: string = 'software-catalog';
 
   static fromConfig(
@@ -51,15 +55,19 @@ export class DefaultCatalogCollator implements DocumentCollator {
     discovery,
     locationTemplate,
     filter,
+    catalogClient,
   }: {
     discovery: PluginEndpointDiscovery;
     locationTemplate?: string;
     filter?: CatalogEntitiesRequest['filter'];
+    catalogClient?: CatalogApi;
   }) {
     this.discovery = discovery;
     this.locationTemplate =
       locationTemplate || '/catalog/:namespace/:kind/:name';
-    this.filterUrl = mapFilterToQueryString(filter);
+    this.filter = filter;
+    this.catalogClient =
+      catalogClient || new CatalogClient({ discoveryApi: discovery });
   }
 
   protected applyArgsToFormat(
@@ -74,10 +82,10 @@ export class DefaultCatalogCollator implements DocumentCollator {
   }
 
   async execute() {
-    const baseUrl = await this.discovery.getBaseUrl('catalog');
-    const res = await fetch(`${baseUrl}/entities${this.filterUrl || ''}`);
-    const entities: Entity[] = await res.json();
-    return entities.map((entity: Entity): CatalogEntityDocument => {
+    const response = await this.catalogClient.getEntities({
+      filter: this.filter,
+    });
+    return response.items.map((entity: Entity): CatalogEntityDocument => {
       return {
         title: entity.metadata.name,
         location: this.applyArgsToFormat(this.locationTemplate, {
@@ -95,18 +103,3 @@ export class DefaultCatalogCollator implements DocumentCollator {
     });
   }
 }
-
-export function mapFilterToQueryString(
-  filter: CatalogEntitiesRequest['filter'],
-): string | undefined {
-  if (!filter) {
-    return undefined;
-  }
-
-  const mappedFilters = Object.entries(filter).map(kvp => {
-    const type = kvp[0];
-    const values = [].concat(kvp[1]);
-    return `${type}=${values.join(',')}`;
-  });
-  return `?filter=${mappedFilters.join(',')}`;
-}