diff --git a/README.md b/README.md
index 94416ff..45ce55c 100644
--- a/README.md
+++ b/README.md
@@ -336,9 +336,17 @@ $redis = new Clue\React\Redis\RedisClient('localhost');
 $redis = new Clue\React\Redis\RedisClient('redis://localhost:6379');
 ```
 
-Redis supports password-based authentication (`AUTH` command). Note that Redis'
-authentication mechanism does not employ a username, so you can pass the
-password `h@llo` URL-encoded (percent-encoded) as part of the URI like this:
+Starting with Redis 6, you can use ACLs and authenticate with both a 
+username and a password. Any URI containing user:pass@ will now invoke 
+the AUTH <user> <pass> command under the hood. For example:
+
+```php
+// Authenticate with username and password (Redis 6+ ACL)
+$redis = new Clue\React\Redis\RedisClient('redis://mauricio:mypass@localhost:6379');
+```
+
+If you omit the username (or use an empty userinfo part), the client will fall back 
+to the legacy AUTH <pass> behavior:
 
 ```php
 // all forms are equivalent
@@ -489,7 +497,15 @@ that eventually *fulfills* with its *results* on success or *rejects* with an
 #### callAsync()
 
 The `callAsync(string $command, string|int|float ...$args): PromiseInterface<mixed>` method can be used to
-invoke a Redis command.
+invoke a Redis command. Note that the `AUTH` command now supports **two** arguments for Redis 6+ ACL mode:
+
+```php
+// authenticate with username + password (Redis 6+)
+$redis->callAsync('AUTH', 'alice', 'hunter2');
+
+// legacy password-only mode
+$redis->callAsync('AUTH', 'hunter2');
+```
 
 For example, the [`GET` command](https://redis.io/commands/get) can be invoked
 like this:
diff --git a/src/Io/Factory.php b/src/Io/Factory.php
index 5a3d692..6602dca 100644
--- a/src/Io/Factory.php
+++ b/src/Io/Factory.php
@@ -96,9 +96,23 @@ public function createClient(string $uri): PromiseInterface
         // use `?password=secret` query or `user:secret@host` password form URL
         if (isset($args['password']) || isset($parts['pass'])) {
             $pass = $args['password'] ?? rawurldecode($parts['pass']); // @phpstan-ignore-line
+
+            $user = null;
+            if (isset($args['username']) || isset($parts['user'])) {
+                $user = $args['username'] ?? rawurldecode($parts['user']); // @phpstan-ignore-line
+            }
+
             \assert(\is_string($pass));
-            $promise = $promise->then(function (StreamingClient $redis) use ($pass, $uri) {
-                return $redis->callAsync('auth', $pass)->then(
+            \assert($user === null || \is_string($user));
+
+            $promise = $promise->then(function (StreamingClient $redis) use ($user, $pass, $uri) {
+                if ($user !== null) {
+                    $authPromise = $redis->callAsync('auth', $user, $pass);
+                } else {
+                    $authPromise = $redis->callAsync('auth', $pass);
+                }
+
+                return $authPromise->then(
                     function () use ($redis) {
                         return $redis;
                     },
@@ -211,4 +225,4 @@ function (\Throwable $e) use ($redis, $uri) {
         // variable assignment needed for legacy PHPStan on PHP 7.1 only
         return $ret;
     }
-}
+}
\ No newline at end of file
diff --git a/tests/Io/FactoryStreamingClientTest.php b/tests/Io/FactoryStreamingClientTest.php
index 4a5ee19..5c7bb3e 100644
--- a/tests/Io/FactoryStreamingClientTest.php
+++ b/tests/Io/FactoryStreamingClientTest.php
@@ -110,7 +110,7 @@ public function testWillWriteSelectCommandIfTargetContainsDbQueryParameter(): vo
     public function testWillWriteAuthCommandIfRedisUriContainsUserInfo(): void
     {
         $stream = $this->createMock(ConnectionInterface::class);
-        $stream->expects($this->once())->method('write')->with("*2\r\n$4\r\nauth\r\n$5\r\nworld\r\n");
+        $stream->expects($this->once())->method('write')->with("*3\r\n$4\r\nauth\r\n$5\r\nhello\r\n$5\r\nworld\r\n");
 
         $loop = $this->createMock(LoopInterface::class);
         $loop->expects($this->once())->method('addTimer');
@@ -124,7 +124,7 @@ public function testWillWriteAuthCommandIfRedisUriContainsUserInfo(): void
     public function testWillWriteAuthCommandIfRedisUriContainsEncodedUserInfo(): void
     {
         $stream = $this->createMock(ConnectionInterface::class);
-        $stream->expects($this->once())->method('write')->with("*2\r\n$4\r\nauth\r\n$5\r\nh@llo\r\n");
+        $stream->expects($this->once())->method('write')->with("*3\r\n$4\r\nauth\r\n$0\r\n\r\n$5\r\nh@llo\r\n");
 
         $loop = $this->createMock(LoopInterface::class);
         $loop->expects($this->once())->method('addTimer');
@@ -166,7 +166,7 @@ public function testWillWriteAuthCommandIfTargetContainsEncodedPasswordQueryPara
     public function testWillWriteAuthCommandIfRedissUriContainsUserInfo(): void
     {
         $stream = $this->createMock(ConnectionInterface::class);
-        $stream->expects($this->once())->method('write')->with("*2\r\n$4\r\nauth\r\n$5\r\nworld\r\n");
+        $stream->expects($this->once())->method('write')->with("*3\r\n$4\r\nauth\r\n$5\r\nhello\r\n$5\r\nworld\r\n");
 
         $loop = $this->createMock(LoopInterface::class);
         $loop->expects($this->once())->method('addTimer');
@@ -203,7 +203,7 @@ public function testWillNotWriteAnyCommandIfRedisUnixUriContainsNoPasswordOrDb()
     public function testWillWriteAuthCommandIfRedisUnixUriContainsUserInfo(): void
     {
         $stream = $this->createMock(ConnectionInterface::class);
-        $stream->expects($this->once())->method('write')->with("*2\r\n$4\r\nauth\r\n$5\r\nworld\r\n");
+        $stream->expects($this->once())->method('write')->with("*3\r\n$4\r\nauth\r\n$5\r\nhello\r\n$5\r\nworld\r\n");
 
         $loop = $this->createMock(LoopInterface::class);
         $loop->expects($this->once())->method('addTimer');
@@ -218,7 +218,7 @@ public function testWillResolveWhenAuthCommandReceivesOkResponseIfRedisUriContai
     {
         $dataHandler = null;
         $stream = $this->createMock(ConnectionInterface::class);
-        $stream->expects($this->once())->method('write')->with("*2\r\n$4\r\nauth\r\n$5\r\nworld\r\n");
+        $stream->expects($this->once())->method('write')->with("*3\r\n$4\r\nauth\r\n$0\r\n\r\n$5\r\nworld\r\n");
         $stream->expects($this->exactly(2))->method('on')->withConsecutive(
             ['data', $this->callback(function ($arg) use (&$dataHandler) {
                 $dataHandler = $arg;
@@ -240,7 +240,7 @@ public function testWillRejectAndCloseAutomaticallyWhenAuthCommandReceivesErrorR
     {
         $dataHandler = null;
         $stream = $this->createMock(ConnectionInterface::class);
-        $stream->expects($this->once())->method('write')->with("*2\r\n$4\r\nauth\r\n$5\r\nworld\r\n");
+        $stream->expects($this->once())->method('write')->with("*3\r\n$4\r\nauth\r\n$0\r\n\r\n$5\r\nworld\r\n");
         $stream->expects($this->once())->method('close');
         $stream->expects($this->exactly(2))->method('on')->withConsecutive(
             ['data', $this->callback(function ($arg) use (&$dataHandler) {
@@ -277,7 +277,7 @@ public function testWillRejectAndCloseAutomaticallyWhenConnectionIsClosedWhileWa
     {
         $closeHandler = null;
         $stream = $this->createMock(ConnectionInterface::class);
-        $stream->expects($this->once())->method('write')->with("*2\r\n$4\r\nauth\r\n$5\r\nworld\r\n");
+        $stream->expects($this->once())->method('write')->with("*3\r\n$4\r\nauth\r\n$0\r\n\r\n$5\r\nworld\r\n");
         $stream->expects($this->once())->method('close');
         $stream->expects($this->exactly(2))->method('on')->withConsecutive(
             ['data', $this->anything()],
@@ -708,4 +708,55 @@ public function testCreateClientWillCancelTimerWhenConnectionRejects(): void
 
         $deferred->reject(new \RuntimeException());
     }
+
+    public function testWillWriteAuthCommandIfTargetContainsUsernameAndPasswordQueryParameter(): void
+    {
+        $stream = $this->createMock(ConnectionInterface::class);
+        $stream->expects($this->once())->method('write')->with("*3\r\n$4\r\nauth\r\n$5\r\nhello\r\n$5\r\nworld\r\n");
+
+        $loop = $this->createMock(LoopInterface::class);
+        $loop->expects($this->once())->method('addTimer');
+        assert($loop instanceof LoopInterface);
+        Loop::set($loop);
+
+        $this->connector
+            ->expects($this->once())
+            ->method('connect')
+            ->with('example.com:6379')
+            ->willReturn(resolve($stream));
+
+        $this->factory->createClient(
+            'redis://example.com?username=hello&password=world'
+        );
+    }
+
+    public function testWillResolveWhenAuthCommandReceivesOkResponseWithUsernameAndPassword(): void
+    {
+            $dataHandler = null;
+            $stream = $this->createMock(ConnectionInterface::class);
+            $stream->expects($this->once())->method('write')->with("*3\r\n$4\r\nauth\r\n$4\r\nuser\r\n$4\r\npass\r\n");
+            $stream->expects($this->exactly(2))->method('on')->withConsecutive(
+                    ['data', $this->callback(function ($cb) use (&$dataHandler) {
+                            $dataHandler = $cb;
+                            return true;
+            })],
+                    ['close', $this->anything()]
+                );
+
+            $this->connector
+                ->expects($this->once())
+                ->method('connect')
+                ->willReturn(resolve($stream));
+
+        $promise = $this->factory->createClient(
+                'redis://user:pass@example.com'
+            );
+
+        $this->assertTrue(is_callable($dataHandler));
+        $dataHandler("+OK\r\n");
+
+        $promise->then($this->expectCallableOnceWith(
+                $this->isInstanceOf(StreamingClient::class)
+            ));
+    }
 }