diff --git a/src/api/routes/experiments.ts b/src/api/routes/experiments.ts
index da83a1c91..015ac16ec 100644
--- a/src/api/routes/experiments.ts
+++ b/src/api/routes/experiments.ts
@@ -35,7 +35,7 @@ router.get("/", route({}), (req: Request, res: Response) => {
 	if (uniqueUsernames) {
 		// hash, revision, bucket, override, population, hash_result, as_mode
 		// bucket 4 is used by the official client, and enables live checking and suggestions, 3 is only live checking
-		data.assignments.push([2476969328, 0, 3, -1, 0, 9267, 0, 0]);
+		data.assignments.push([2476969328, 0, 4, -1, 0, 9267, 0, 0]);
 	}
 	res.send(data);
 });
diff --git a/src/api/routes/unique-username/username-attempt-unauthed.ts b/src/api/routes/unique-username/username-attempt-unauthed.ts
index a1f63a691..3af1fa883 100644
--- a/src/api/routes/unique-username/username-attempt-unauthed.ts
+++ b/src/api/routes/unique-username/username-attempt-unauthed.ts
@@ -25,7 +25,7 @@ router.post(
 		}
 
 		res.json({
-			taken: !User.isUsernameAvailable(body.username),
+			taken: !(await User.isUsernameAvailable(body.username)),
 		});
 	},
 );
diff --git a/src/api/routes/users/@me/index.ts b/src/api/routes/users/@me/index.ts
index ec0a050a8..9601005e6 100644
--- a/src/api/routes/users/@me/index.ts
+++ b/src/api/routes/users/@me/index.ts
@@ -152,7 +152,7 @@ router.patch(
                 }
 
                 // check if username is already taken (pomelo only)
-				if (!User.isUsernameAvailable(body.username))
+				if (!(await User.isUsernameAvailable(body.username)))
                     throw FieldErrors({
                         username: {
                             code: "USERNAME_ALREADY_TAKEN",
diff --git a/src/util/entities/User.ts b/src/util/entities/User.ts
index 49de9feee..dd66f7d26 100644
--- a/src/util/entities/User.ts
+++ b/src/util/entities/User.ts
@@ -318,7 +318,7 @@ export class User extends BaseClass {
 
 		if (uniqueUsernames) {
 			// check if there is already an account with this username
-			if (!User.isUsernameAvailable(username))
+			if (!(await User.isUsernameAvailable(username)))
 				throw FieldErrors({
 					username: {
 						code: "USERNAME_ALREADY_TAKEN",
@@ -439,10 +439,13 @@ export class User extends BaseClass {
     }
 
     static async isUsernameAvailable(username: string) {
-        const user = await User.findOne({
-            where: { username },
-            select: ["id"],
+		// TODO: implement regex check?
+		const count = await User.count({
+			where: {
+				username: username.toLowerCase(),
+			},
         });
-        return !user;
+
+		return count === 0;
     }
 }