diff --git a/packages/backend/src/core/activitypub/ApRendererService.ts b/packages/backend/src/core/activitypub/ApRendererService.ts
index 55d1054de9..499a163d6c 100644
--- a/packages/backend/src/core/activitypub/ApRendererService.ts
+++ b/packages/backend/src/core/activitypub/ApRendererService.ts
@@ -526,6 +526,7 @@ export class ApRendererService {
 			publicKey: this.renderKey(user, keypair, '#main-key'),
 			isCat: user.isCat,
 			noindex: user.noindex,
+			indexable: !user.noindex,
 			speakAsCat: user.speakAsCat,
 			attachment: attachment.length ? attachment : undefined,
 		};
diff --git a/packages/backend/src/core/activitypub/misc/contexts.ts b/packages/backend/src/core/activitypub/misc/contexts.ts
index 815b20b910..86a665732a 100644
--- a/packages/backend/src/core/activitypub/misc/contexts.ts
+++ b/packages/backend/src/core/activitypub/misc/contexts.ts
@@ -545,6 +545,7 @@ const extension_context_definition = {
 	Emoji: 'toot:Emoji',
 	featured: 'toot:featured',
 	discoverable: 'toot:discoverable',
+	indexable: 'toot:indexable',
 	// schema
 	schema: 'http://schema.org#',
 	PropertyValue: 'schema:PropertyValue',