diff --git a/src/queue/index.ts b/src/queue/index.ts
index 4aa1dc032d..94efb3634a 100644
--- a/src/queue/index.ts
+++ b/src/queue/index.ts
@@ -19,12 +19,12 @@ export function createHttp(data) {
 }
 
 export function deliver(user, content, to) {
-	return createHttp({
+	createHttp({
 		type: 'deliver',
 		user,
 		content,
 		to
-	});
+	}).save();
 }
 
 export default function() {
diff --git a/src/services/following/create.ts b/src/services/following/create.ts
index 3289e31294..375b028912 100644
--- a/src/services/following/create.ts
+++ b/src/services/following/create.ts
@@ -58,11 +58,11 @@ export default async function(follower: IUser, followee: IUser, activity?) {
 
 	if (isLocalUser(follower) && isRemoteUser(followee)) {
 		const content = pack(renderFollow(follower, followee));
-		deliver(follower, content, followee.inbox).save();
+		deliver(follower, content, followee.inbox);
 	}
 
 	if (isRemoteUser(follower) && isLocalUser(followee)) {
 		const content = pack(renderAccept(activity));
-		deliver(followee, content, follower.inbox).save();
+		deliver(followee, content, follower.inbox);
 	}
 }
diff --git a/src/services/following/delete.ts b/src/services/following/delete.ts
index 8b6c56816a..c0c99fbed5 100644
--- a/src/services/following/delete.ts
+++ b/src/services/following/delete.ts
@@ -57,6 +57,6 @@ export default async function(follower: IUser, followee: IUser, activity?) {
 
 	if (isLocalUser(follower) && isRemoteUser(followee)) {
 		const content = pack(renderUndo(renderFollow(follower, followee)));
-		deliver(follower, content, followee.inbox).save();
+		deliver(follower, content, followee.inbox);
 	}
 }
diff --git a/src/services/note/create.ts b/src/services/note/create.ts
index 603851adb5..781337daf4 100644
--- a/src/services/note/create.ts
+++ b/src/services/note/create.ts
@@ -136,12 +136,12 @@ export default async (user: IUser, data: {
 
 			// 投稿がリプライかつ投稿者がローカルユーザーかつリプライ先の投稿の投稿者がリモートユーザーなら配送
 			if (data.reply && isLocalUser(user) && isRemoteUser(data.reply._user)) {
-				deliver(user, await render(), data.reply._user.inbox).save();
+				deliver(user, await render(), data.reply._user.inbox);
 			}
 
 			// 投稿がRenoteかつ投稿者がローカルユーザーかつRenote元の投稿の投稿者がリモートユーザーなら配送
 			if (data.renote && isLocalUser(user) && isRemoteUser(data.renote._user)) {
-				deliver(user, await render(), data.renote._user.inbox).save();
+				deliver(user, await render(), data.renote._user.inbox);
 			}
 
 			Promise.all(followers.map(async follower => {
@@ -153,7 +153,7 @@ export default async (user: IUser, data: {
 				} else {
 					// フォロワーがリモートユーザーかつ投稿者がローカルユーザーなら投稿を配信
 					if (isLocalUser(user)) {
-						deliver(user, await render(), follower.inbox).save();
+						deliver(user, await render(), follower.inbox);
 					}
 				}
 			}));
diff --git a/src/services/note/reaction/create.ts b/src/services/note/reaction/create.ts
index 69a14248da..dd3d4be8b7 100644
--- a/src/services/note/reaction/create.ts
+++ b/src/services/note/reaction/create.ts
@@ -9,6 +9,7 @@ import watch from '../watch';
 import renderLike from '../../../remote/activitypub/renderer/like';
 import { deliver } from '../../../queue';
 import pack from '../../../remote/activitypub/renderer';
+import { MongoError } from 'mongodb';
 
 export default async (user: IUser, note: INote, reaction: string) => new Promise(async (res, rej) => {
 	// Myself
@@ -16,23 +17,23 @@ export default async (user: IUser, note: INote, reaction: string) => new Promise
 		return rej('cannot react to my note');
 	}
 
-	// if already reacted
-	const exist = await NoteReaction.findOne({
-		noteId: note._id,
-		userId: user._id
-	});
-
-	if (exist !== null) {
-		return rej('already reacted');
-	}
-
 	// Create reaction
-	await NoteReaction.insert({
-		createdAt: new Date(),
-		noteId: note._id,
-		userId: user._id,
-		reaction
-	});
+	try {
+		await NoteReaction.insert({
+			createdAt: new Date(),
+			noteId: note._id,
+			userId: user._id,
+			reaction
+		});
+	} catch (e) {
+		// duplicate key error
+		if (e instanceof MongoError && e.code === 11000) {
+			return rej('already reacted');
+		}
+
+		console.error(e);
+		return rej('something happened');
+	}
 
 	res();
 
@@ -86,7 +87,7 @@ export default async (user: IUser, note: INote, reaction: string) => new Promise
 	// リアクターがローカルユーザーかつリアクション対象がリモートユーザーの投稿なら配送
 	if (isLocalUser(user) && isRemoteUser(note._user)) {
 		const content = pack(renderLike(user, note));
-		deliver(user, content, note._user.inbox).save();
+		deliver(user, content, note._user.inbox);
 	}
 	//#endregion
 });