diff --git a/packages/backend/src/server/api/endpoints/admin/reports/resolve.ts b/packages/backend/src/server/api/endpoints/admin/reports/resolve.ts
index 705dd5a37..96dd3d612 100644
--- a/packages/backend/src/server/api/endpoints/admin/reports/resolve.ts
+++ b/packages/backend/src/server/api/endpoints/admin/reports/resolve.ts
@@ -29,7 +29,7 @@ export default define(meta, paramDef, async (ps, me) => {
 		const actor = await getInstanceActor();
 		const targetUser = await Users.findOneByOrFail({ id: report.targetUserId });
 
-		deliver(renderActivity(renderFlag(actor, report)), targetUser.inbox);
+		await deliver(renderActivity(renderFlag(actor, report)), targetUser.inbox);
 	}
 
 	await AbuseUserReports.update(report.id, {
diff --git a/packages/backend/src/server/api/endpoints/notes/polls/vote.ts b/packages/backend/src/server/api/endpoints/notes/polls/vote.ts
index c5ad95af5..eadf97225 100644
--- a/packages/backend/src/server/api/endpoints/notes/polls/vote.ts
+++ b/packages/backend/src/server/api/endpoints/notes/polls/vote.ts
@@ -133,7 +133,7 @@ export default define(meta, paramDef, async (ps, user) => {
 	if (note.userHost != null) {
 		const pollOwner = await Users.findOneByOrFail({ id: note.userId }) as IRemoteUser;
 
-		deliver(renderActivity(await renderVote(user, vote, note, poll, pollOwner)), pollOwner.inbox);
+		await deliver(renderActivity(await renderVote(user, vote, note, poll, pollOwner)), pollOwner.inbox);
 	}
 
 	// リモートフォロワーにUpdate配信
diff --git a/packages/backend/src/services/blocking/delete.ts b/packages/backend/src/services/blocking/delete.ts
index 804739104..c37b83313 100644
--- a/packages/backend/src/services/blocking/delete.ts
+++ b/packages/backend/src/services/blocking/delete.ts
@@ -29,6 +29,6 @@ export default async function(blocker: User, blockee: User) {
 	// deliver if remote bloking
 	if (Users.isLocalUser(blocker) && Users.isRemoteUser(blockee)) {
 		const content = renderActivity(renderUndo(renderBlock(blocking), blocker));
-		deliver(content, blockee.inbox);
+		await deliver(content, blockee.inbox);
 	}
 }
diff --git a/packages/backend/src/services/following/requests/accept.ts b/packages/backend/src/services/following/requests/accept.ts
index 6e5c02364..beb10a56f 100644
--- a/packages/backend/src/services/following/requests/accept.ts
+++ b/packages/backend/src/services/following/requests/accept.ts
@@ -27,7 +27,7 @@ export async function acceptFollowRequest(followee: User, follower: User): Promi
 
 	if (Users.isRemoteUser(follower) && Users.isLocalUser(followee)) {
 		const content = renderActivity(renderAccept(renderFollow(follower, followee, request.requestId!), followee));
-		deliver(content, follower.inbox);
+		await deliver(content, follower.inbox);
 	}
 
 	Users.pack(followee.id, followee, {
diff --git a/packages/backend/src/services/following/requests/cancel.ts b/packages/backend/src/services/following/requests/cancel.ts
index ae1fd90bc..31193a911 100644
--- a/packages/backend/src/services/following/requests/cancel.ts
+++ b/packages/backend/src/services/following/requests/cancel.ts
@@ -17,7 +17,7 @@ export async function cancelFollowRequest(followee: User, follower: User): Promi
 		const content = renderActivity(renderUndo(renderFollow(follower, followee), follower));
 
 		if (Users.isLocalUser(follower)) {
-			deliver(content, followee.inbox);
+			await deliver(content, followee.inbox);
 		}
 	}
 
diff --git a/packages/backend/src/services/following/requests/create.ts b/packages/backend/src/services/following/requests/create.ts
index 396089b1a..0f92db2b0 100644
--- a/packages/backend/src/services/following/requests/create.ts
+++ b/packages/backend/src/services/following/requests/create.ts
@@ -64,6 +64,6 @@ export async function createFollowRequest(follower: User, followee: User, reques
 
 	if (Users.isLocalUser(follower) && Users.isRemoteUser(followee)) {
 		const content = renderActivity(renderFollow(follower, followee));
-		deliver(content, followee.inbox);
+		await deliver(content, followee.inbox);
 	}
 }
diff --git a/packages/backend/src/services/messages/create.ts b/packages/backend/src/services/messages/create.ts
index 67451bce1..2f51858ca 100644
--- a/packages/backend/src/services/messages/create.ts
+++ b/packages/backend/src/services/messages/create.ts
@@ -97,7 +97,7 @@ export async function createMessage(user: { id: User['id']; host: User['host'];
 
 		const activity = renderActivity(renderCreate(await renderNote(note, false, true), note));
 
-		deliver(activity, recipientUser.inbox);
+		await deliver(activity, recipientUser.inbox);
 	}
 	return messageObj;
 }
diff --git a/packages/backend/src/services/messages/delete.ts b/packages/backend/src/services/messages/delete.ts
index 1082ba8a7..acbc5e71a 100644
--- a/packages/backend/src/services/messages/delete.ts
+++ b/packages/backend/src/services/messages/delete.ts
@@ -22,7 +22,7 @@ async function postDeleteMessage(message: MessagingMessage): Promise<void> {
 
 		if (Users.isLocalUser(user) && Users.isRemoteUser(recipient)) {
 			const activity = renderActivity(renderDelete(renderTombstone(`${config.url}/notes/${message.id}`), user));
-			deliver(activity, recipient.inbox);
+			await deliver(activity, recipient.inbox);
 		}
 	} else if (message.groupId) {
 		publishGroupMessagingStream(message.groupId, 'deleted', message.id);
diff --git a/packages/backend/src/services/relay.ts b/packages/backend/src/services/relay.ts
index 76adb991c..8c580ea7d 100644
--- a/packages/backend/src/services/relay.ts
+++ b/packages/backend/src/services/relay.ts
@@ -37,7 +37,7 @@ export async function addRelay(inbox: string): Promise<Relay> {
 
 	const relayActor = await getRelayActor();
 	const activity = renderActivity(renderFollowRelay(relay, relayActor));
-	deliver(activity, relay.inbox);
+	await deliver(activity, relay.inbox);
 
 	return relay;
 }
@@ -53,7 +53,7 @@ export async function removeRelay(inbox: string): Promise<void> {
 
 	const relayActor = await getRelayActor();
 	const activity = renderActivity(renderUndo(renderFollowRelay(relay, relayActor), relayActor));
-	deliver(activity, relay.inbox);
+	await deliver(activity, relay.inbox);
 
 	await Relays.delete(relay.id);
 }
@@ -89,9 +89,9 @@ export async function deliverToRelays(user: { id: User['id']; host: null; }, act
 
 	const signed = await attachLdSignature(copy, user);
 
-	for (const relay of relays) {
-		deliver(signed, relay.inbox);
-	}
+	await Promise.all(relays.map(relay =>
+		deliver(signed, relay.inbox)
+	));
 }
 
 export async function deliverMultipleToRelays(user: User, activities: any[]): Promise<void> {
@@ -107,7 +107,7 @@ export async function deliverMultipleToRelays(user: User, activities: any[]): Pr
 		return attachLdSignature(copy, user);
 	}));
 
-	for (const relay of relays) {
-		deliver(content, relay.inbox);
-	}
+	await Promise.all(relays.map(relay =>
+		deliver(content, relay.inbox)
+	));
 }
diff --git a/packages/backend/src/services/unsuspend-user.ts b/packages/backend/src/services/unsuspend-user.ts
index 85a886be1..472ed7484 100644
--- a/packages/backend/src/services/unsuspend-user.ts
+++ b/packages/backend/src/services/unsuspend-user.ts
@@ -32,7 +32,7 @@ export async function doPostUnsuspend(user: User): Promise<void> {
 		}
 
 		for (const inbox of queue) {
-			deliver(content, inbox);
+			await deliver(content, inbox);
 		}
 	}
 }