diff --git a/plugins/github-issues/src/api/gitHubIssuesApi.test.ts b/plugins/github-issues/src/api/gitHubIssuesApi.test.ts
index 070e9ab2f6..b2be54a2d1 100644
--- a/plugins/github-issues/src/api/gitHubIssuesApi.test.ts
+++ b/plugins/github-issues/src/api/gitHubIssuesApi.test.ts
@@ -20,7 +20,8 @@ jest.mock('octokit', () => ({
 
 import { ConfigApi, ErrorApi } from '@backstage/core-plugin-api';
 import { ForwardedError } from '@backstage/errors';
-import { gitHubIssuesApi } from './gitHubIssuesApi';
+import { createFilterByClause, gitHubIssuesApi } from './gitHubIssuesApi';
+import type { GithubIssuesFilters } from './gitHubIssuesApi';
 
 function getFragment(
   filterBy = '',
@@ -141,6 +142,30 @@ describe('gitHubIssuesApi', () => {
         getFragment(expectedFilterBy, expectedOrderBy),
       );
     });
+
+    describe('filterBy', () => {
+      const cases: [GithubIssuesFilters | undefined, string][] = [
+        [{}, ''],
+        [undefined, ''],
+        [{ states: ['OPEN'] }, 'states: OPEN'],
+        [
+          { labels: ['bug', 'enhancement'], assignee: 'someone' },
+          `labels: [ \"bug\", \"enhancement\"], assignee: "someone"`,
+        ],
+        [
+          {
+            createdBy: 'someone',
+            mentioned: 'someone else',
+            milestone: 'milestone',
+          },
+          `createdBy: \"someone\", mentioned: \"someone else\", milestone: \"milestone\"`,
+        ],
+      ];
+
+      test.each(cases)('filterBy(%s) should be %s', (filterBy, expected) => {
+        expect(createFilterByClause(filterBy)).toEqual(expected);
+      });
+    });
   });
 
   it('should return data for repos with successfully retrieved issues when GitHub returns partial failure', async () => {
diff --git a/plugins/github-issues/src/api/gitHubIssuesApi.ts b/plugins/github-issues/src/api/gitHubIssuesApi.ts
index d80ec3bce8..12d38ad3c8 100644
--- a/plugins/github-issues/src/api/gitHubIssuesApi.ts
+++ b/plugins/github-issues/src/api/gitHubIssuesApi.ts
@@ -199,22 +199,20 @@ function formatFilterValue(
   return typeof value === 'string' ? `\"${value}\"` : `${value}`;
 }
 
-function createFilterByClause(filterBy?: GithubIssuesFilters): string {
+/** @internal */
+export function createFilterByClause(filterBy?: GithubIssuesFilters): string {
   if (!filterBy) {
     return '';
   }
 
   return Object.entries(filterBy)
-    .flatMap(([field, value]) => {
-      if (!value) {
-        return [];
-      }
-
+    .filter(value => value)
+    .map(([field, value]) => {
       if (field === 'states') {
-        return [`${field}: ${value.join(', ')}`];
+        return `${field}: ${value.join(', ')}`;
       }
 
-      return [`${field}: ${formatFilterValue(value)}`];
+      return `${field}: ${formatFilterValue(value)}`;
     })
     .join(', ');
 }