diff --git a/packages/backend/src/core/QueueService.ts b/packages/backend/src/core/QueueService.ts
index cd20195481..13d9d71233 100644
--- a/packages/backend/src/core/QueueService.ts
+++ b/packages/backend/src/core/QueueService.ts
@@ -62,6 +62,8 @@ export class QueueService {
 	 */
 	@bindThis
 	public async deliverMany(user: ThinUser, content: IActivity | null, inboxes: Map<string, boolean>) {
+		if (content == null) return null;
+
 		const opts = {
 			attempts: this.config.deliverJobMaxAttempts ?? 12,
 			timeout: 1 * 60 * 1000,	// 1min