diff --git a/src/utils/__snapshots__/manifest.test.ts.snap b/src/utils/__snapshots__/manifest.test.ts.snap
index 20edf22..53ea9c6 100644
--- a/src/utils/__snapshots__/manifest.test.ts.snap
+++ b/src/utils/__snapshots__/manifest.test.ts.snap
@@ -1,5 +1,16 @@
 // Jest Snapshot v1, https://jestjs.io/docs/snapshot-testing
 
+exports[`buildManifest has checked includeExternalUrls 1`] = `
+[
+  {
+    "default": "checked",
+    "key": "includeExternalUrls",
+    "title": "Include external URLs from results",
+    "type": "checkbox",
+  },
+]
+`;
+
 exports[`buildManifest has checked source with appropriate config 1`] = `
 [
   {
@@ -19,6 +30,7 @@ exports[`buildManifest has checked source with appropriate config 1`] = `
     "type": "checkbox",
   },
   {
+    "default": "checked",
     "key": "includeExternalUrls",
     "title": "Include external URLs from results",
     "type": "checkbox",
@@ -50,3 +62,13 @@ exports[`buildManifest has unchecked source without a config 1`] = `
   },
 ]
 `;
+
+exports[`buildManifest includeExternalUrls is unchecked by default 1`] = `
+[
+  {
+    "key": "includeExternalUrls",
+    "title": "Include external URLs from results",
+    "type": "checkbox",
+  },
+]
+`;
diff --git a/src/utils/manifest.test.ts b/src/utils/manifest.test.ts
index 4d46fc7..6257e3b 100644
--- a/src/utils/manifest.test.ts
+++ b/src/utils/manifest.test.ts
@@ -23,7 +23,19 @@ describe('buildManifest', () => {
       new StreamKiste(fetcher),
       new MeineCloud(fetcher),
     ];
-    const manifest = buildManifest(sources, { de: 'on' });
+    const manifest = buildManifest(sources, { de: 'on', includeExternalUrls: 'on' });
+
+    expect(manifest.config).toMatchSnapshot();
+  });
+
+  test('includeExternalUrls is unchecked by default', () => {
+    const manifest = buildManifest([], {});
+
+    expect(manifest.config).toMatchSnapshot();
+  });
+
+  test('has checked includeExternalUrls', () => {
+    const manifest = buildManifest([], { includeExternalUrls: 'on' });
 
     expect(manifest.config).toMatchSnapshot();
   });
diff --git a/src/utils/manifest.ts b/src/utils/manifest.ts
index a0b9e70..eb5152b 100644
--- a/src/utils/manifest.ts
+++ b/src/utils/manifest.ts
@@ -54,6 +54,7 @@ export const buildManifest = (sources: Source[], config: Config): ManifestWithCo
     key: 'includeExternalUrls',
     type: 'checkbox',
     title: 'Include external URLs from results',
+    ...('includeExternalUrls' in config && { default: 'checked' }),
   });
 
   return manifest;