diff --git a/packages/backend/src/core/activitypub/misc/contexts.ts b/packages/backend/src/core/activitypub/misc/contexts.ts
index cedd1d8dd5..fa003b1791 100644
--- a/packages/backend/src/core/activitypub/misc/contexts.ts
+++ b/packages/backend/src/core/activitypub/misc/contexts.ts
@@ -540,6 +540,10 @@ const extension_context_definition = {
 	quoteUrl: 'as:quoteUrl',
 	fedibird: 'http://fedibird.com/ns#',
 	quoteUri: 'fedibird:quoteUri',
+	quote: {
+		'@id': 'https://w3id.org/fep/044f#quote',
+		'@type': '@id',
+	},
 	// Mastodon
 	toot: 'http://joinmastodon.org/ns#',
 	Emoji: 'toot:Emoji',
diff --git a/packages/backend/src/core/activitypub/type.ts b/packages/backend/src/core/activitypub/type.ts
index cc7599d394..cdf4a65baa 100644
--- a/packages/backend/src/core/activitypub/type.ts
+++ b/packages/backend/src/core/activitypub/type.ts
@@ -204,6 +204,7 @@ export interface IPost extends IObject {
 	_misskey_content?: string;
 	quoteUrl?: string;
 	quoteUri?: string;
+	quote?: string;
 	updated?: string;
 }