diff --git a/packages/backend/src/server/api/endpoints/channels/timeline.ts b/packages/backend/src/server/api/endpoints/channels/timeline.ts
index 02429c2bd9..9ef494d6d8 100644
--- a/packages/backend/src/server/api/endpoints/channels/timeline.ts
+++ b/packages/backend/src/server/api/endpoints/channels/timeline.ts
@@ -52,6 +52,7 @@ export const paramDef = {
 		untilId: { type: 'string', format: 'misskey:id' },
 		sinceDate: { type: 'integer' },
 		untilDate: { type: 'integer' },
+		allowPartial: { type: 'boolean', default: false }, // true is recommended but for compatibility false by default
 	},
 	required: ['channelId'],
 } as const;
@@ -103,6 +104,7 @@ export default class extends Endpoint<typeof meta, typeof paramDef> { // eslint-
 				untilId,
 				sinceId,
 				limit: ps.limit,
+				allowPartial: ps.allowPartial,
 				me,
 				useDbFallback: true,
 				redisTimelines: [`channelTimeline:${channel.id}`],