diff --git a/packages/backend/src/core/activitypub/ApRendererService.ts b/packages/backend/src/core/activitypub/ApRendererService.ts
index 4d8e075a3..0b904889a 100644
--- a/packages/backend/src/core/activitypub/ApRendererService.ts
+++ b/packages/backend/src/core/activitypub/ApRendererService.ts
@@ -171,6 +171,7 @@ export class ApRendererService {
 			mediaType: file.webpublicType ?? file.type,
 			url: this.driveFileEntityService.getPublicUrl(file),
 			name: file.comment,
+			description: file.comment,
 		};
 	}
 
@@ -746,6 +747,7 @@ export class ApRendererService {
 			summary: summary ?? undefined,
 			content: content ?? undefined,
 			updated: note.updatedAt?.toISOString(),
+			edited_at: note.updatedAt?.toISOString(),
 			_misskey_content: text,
 			source: {
 				content: text,
diff --git a/packages/backend/src/core/activitypub/type.ts b/packages/backend/src/core/activitypub/type.ts
index b5ba8cd5a..1ed28f21b 100644
--- a/packages/backend/src/core/activitypub/type.ts
+++ b/packages/backend/src/core/activitypub/type.ts
@@ -121,6 +121,7 @@ export interface IPost extends IObject {
 	quoteUrl?: string;
 	quoteUri?: string;
 	updated?: string;
+	edited_at?: string;
 }
 
 export interface IQuestion extends IObject {
@@ -249,6 +250,7 @@ export interface IApDocument extends IObject {
 	type: 'Document';
 	name: string | null;
 	mediaType: string;
+	description: string | null;
 }
 
 export interface IApImage extends IObject {