diff --git a/plugins/search-backend/src/service/router.test.ts b/plugins/search-backend/src/service/router.test.ts
index 1437e65b84..100dee9117 100644
--- a/plugins/search-backend/src/service/router.test.ts
+++ b/plugins/search-backend/src/service/router.test.ts
@@ -18,7 +18,9 @@ import { getVoidLogger } from '@backstage/backend-common';
 import { ConfigReader } from '@backstage/config';
 import { PermissionEvaluator } from '@backstage/plugin-permission-common';
 import { IndexBuilder } from '@backstage/plugin-search-backend-node';
-import { SearchEngine } from '@backstage/plugin-search-common';
+import {
+  SearchEngine,
+} from '@backstage/plugin-search-common';
 import express from 'express';
 import request from 'supertest';
 
@@ -148,6 +150,25 @@ describe('createRouter', () => {
       });
     });
 
+    it('is less restrictive with unknown keys on query endpoint', async () => {
+      const queryString =
+        'term=test&%5BdocType%5D%5B0%5D=Service&filters%5BdocType%5D%5B0%5D=filter1&unknownKey1%5B2%5D=unknownValue1&unknownKey1%5B3%5D=unknownValue2&unknownKey2=unknownValue1&pageCursor';
+      const response = await request(app).get(`/query?${queryString}`);
+      const firstArg: Object = {
+        docType: ['Service'],
+        filters: { docType: ['filter1'] },
+        pageCursor: '',
+        term: 'test',
+        unknownKey1: ['unknownValue1', 'unknownValue2'],
+        unknownKey2: 'unknownValue1',
+      };
+      const secondArg = {
+        token: undefined,
+      };
+      expect(response.status).toEqual(200);
+      expect(mockSearchEngine.query).toHaveBeenCalledWith(firstArg, secondArg);
+    });
+
     describe('search result filtering', () => {
       beforeAll(async () => {
         const logger = getVoidLogger();
diff --git a/plugins/search-backend/src/service/router.ts b/plugins/search-backend/src/service/router.ts
index cf9abff675..87da80d8f5 100644
--- a/plugins/search-backend/src/service/router.ts
+++ b/plugins/search-backend/src/service/router.ts
@@ -133,7 +133,7 @@ export async function createRouter(
       req: express.Request,
       res: express.Response<SearchResultSet | ErrorResponseBody>,
     ) => {
-      const parseResult = requestSchema.safeParse(req.query);
+      const parseResult = requestSchema.passthrough().safeParse(req.query);
 
       if (!parseResult.success) {
         throw new InputError(`Invalid query string: ${parseResult.error}`);