diff --git a/packages/backend/package.json b/packages/backend/package.json
index f7d19d85b2..b584a56910 100644
--- a/packages/backend/package.json
+++ b/packages/backend/package.json
@@ -112,6 +112,7 @@
 		"ratelimiter": "3.4.1",
 		"re2": "1.19.0",
 		"redis-lock": "0.1.4",
+		"redis-semaphore": "5.3.1",
 		"reflect-metadata": "0.1.13",
 		"rename": "1.0.4",
 		"rndstr": "1.0.0",
diff --git a/packages/backend/src/services/note/create.ts b/packages/backend/src/services/note/create.ts
index defd9742e2..f00678ce22 100644
--- a/packages/backend/src/services/note/create.ts
+++ b/packages/backend/src/services/note/create.ts
@@ -69,6 +69,7 @@ import { getActiveWebhooks } from "@/misc/webhook-cache.js";
 import { shouldSilenceInstance } from "@/misc/should-block-instance.js";
 import meilisearch from "../../db/meilisearch.js";
 import { redisClient } from "@/db/redis.js";
+import { Mutex } from "redis-semaphore";
 
 const mutedWordsCache = new Cache<
 	{ userId: UserProfile["userId"]; mutedWords: UserProfile["mutedWords"] }[]
@@ -461,58 +462,43 @@ export default async (
 			}
 
 			if (!dontFederateInitially) {
+				let publishKey: string;
+				let noteToPublish: Note;
 				const relays = await getCachedRelays();
+
 				// Some relays (e.g., aode-relay) deliver posts by boosting them as
 				// Announce activities. In that case, user is the relay's actor.
 				const boostedByRelay =
 					!!user.inbox &&
 					relays.map((relay) => relay.inbox).includes(user.inbox);
 
-				if (!note.uri) {
-					// Publish if the post is local
-					publishNotesStream(note);
-				} else if (boostedByRelay && data.renote?.uri) {
-					// Use Redis transaction for atomicity
-					await redisClient.watch(`publishedNote:${data.renote.uri}`);
-					const exists = await redisClient.exists(
-						`publishedNote:${data.renote.uri}`,
-					);
-					if (exists === 0) {
-						// Start the transaction
-						const transaction = redisClient.multi();
-						const key = `publishedNote:${data.renote.uri}`;
-						transaction.set(key, 1, "EX", 30);
-						// Execute the transaction
-						transaction.exec((err, replies) => {
-							// Publish after setting the key in Redis
-							if (!err && data.renote) {
-								publishNotesStream(data.renote);
-							}
-						});
-					} else {
-						// Abort the transaction
-						redisClient.unwatch();
-					}
-				} else if (!boostedByRelay && note.uri) {
-					// Use Redis transaction for atomicity
-					await redisClient.watch(`publishedNote:${note.uri}`);
-					const exists = await redisClient.exists(`publishedNote:${note.uri}`);
-					if (exists === 0) {
-						// Start the transaction
-						const transaction = redisClient.multi();
-						const key = `publishedNote:${note.uri}`;
-						transaction.set(key, 1, "EX", 30);
-						// Execute the transaction
-						transaction.exec((err, replies) => {
-							// Publish after setting the key in Redis
-							if (!err) {
-								publishNotesStream(note);
-							}
-						});
-					} else {
-						// Abort the transaction
-						redisClient.unwatch();
+				if (boostedByRelay && data.renote && data.renote.userHost) {
+					publishKey = `publishedNote:${data.renote.id}`;
+					noteToPublish = data.renote;
+				} else {
+					publishKey = `publishedNote:${note.id}`;
+					noteToPublish = note;
+				}
+
+				const lock = new Mutex(redisClient, "publishedNote");
+				await lock.acquire();
+				try {
+					const published = (await redisClient.get(publishKey)) !== null;
+					if (!published) {
+						await redisClient.set(publishKey, "done", "EX", 30);
+						if (noteToPublish.renoteId) {
+							// Prevents other threads from publishing the boosting post
+							await redisClient.set(
+								`publishedNote:${noteToPublish.renoteId}`,
+								"done",
+								"EX",
+								30,
+							);
+						}
+						publishNotesStream(noteToPublish);
 					}
+				} finally {
+					await lock.release();
 				}
 			}
 			if (note.replyId != null) {
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index 760931858b..1002a6f958 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -339,6 +339,9 @@ importers:
       redis-lock:
         specifier: 0.1.4
         version: 0.1.4
+      redis-semaphore:
+        specifier: 5.3.1
+        version: 5.3.1(ioredis@5.3.2)
       reflect-metadata:
         specifier: 0.1.13
         version: 0.1.13
@@ -2666,6 +2669,7 @@ packages:
     engines: {node: '>=10'}
     cpu: [arm64]
     os: [android]
+    requiresBuild: true
     dependencies:
       '@swc/wasm': 1.2.130
 
@@ -2772,6 +2776,7 @@ packages:
 
   /@swc/wasm@1.2.130:
     resolution: {integrity: sha512-rNcJsBxS70+pv8YUWwf5fRlWX6JoY/HJc25HD/F8m6Kv7XhJdqPPMhyX6TKkUBPAG7TWlZYoxa+rHAjPy4Cj3Q==}
+    requiresBuild: true
 
   /@syuilo/aiscript@0.11.1:
     resolution: {integrity: sha512-chwOIA3yLUKvOB0G611hjLArKTeOWNmTm3lHERSaDW1d+dS6do56naX6Lkwy2UpnwWC0qzeNSgg35elk6t2gZg==}
@@ -12831,6 +12836,18 @@ packages:
     dependencies:
       redis-errors: 1.2.0
 
+  /redis-semaphore@5.3.1(ioredis@5.3.2):
+    resolution: {integrity: sha512-oUpxxfxSbh5eT0mvVpz2d4Qlg2CsaoQkeo80/v6CU2l97zO0u6NPgc9/zQZa9KGR3/93b0igtSct3hEFh8Ei8w==}
+    engines: {node: '>= 14.17.0'}
+    peerDependencies:
+      ioredis: ^4.1.0 || ^5
+    dependencies:
+      debug: 4.3.4(supports-color@8.1.1)
+      ioredis: 5.3.2
+    transitivePeerDependencies:
+      - supports-color
+    dev: false
+
   /redis@4.6.7:
     resolution: {integrity: sha512-KrkuNJNpCwRm5vFJh0tteMxW8SaUzkm5fBH7eL5hd/D0fAkzvapxbfGPP/r+4JAXdQuX7nebsBkBqA2RHB7Usw==}
     dependencies: