diff --git a/src/Symfony/Component/Notifier/Bridge/Telegram/Tests/TelegramTransportFactoryTest.php b/src/Symfony/Component/Notifier/Bridge/Telegram/Tests/TelegramTransportFactoryTest.php
new file mode 100644
index 0000000000000..c74d38f2f6882
--- /dev/null
+++ b/src/Symfony/Component/Notifier/Bridge/Telegram/Tests/TelegramTransportFactoryTest.php
@@ -0,0 +1,65 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\Notifier\Bridge\Telegram\Tests;
+
+use PHPUnit\Framework\TestCase;
+use Symfony\Component\Notifier\Bridge\Telegram\TelegramTransportFactory;
+use Symfony\Component\Notifier\Exception\IncompleteDsnException;
+use Symfony\Component\Notifier\Exception\UnsupportedSchemeException;
+use Symfony\Component\Notifier\Transport\Dsn;
+
+final class TelegramTransportFactoryTest extends TestCase
+{
+    public function testCreateWithDsn(): void
+    {
+        $factory = new TelegramTransportFactory();
+
+        $host = 'testHost';
+        $channel = 'testChannel';
+
+        $transport = $factory->create(Dsn::fromString(sprintf('telegram://%s@%s/?channel=%s', 'testUser:testPassword', $host, $channel)));
+
+        $this->assertSame(sprintf('telegram://%s?channel=%s', $host, $channel), (string) $transport);
+    }
+
+    public function testCreateWithNoPasswordThrowsMalformed(): void
+    {
+        $factory = new TelegramTransportFactory();
+
+        $this->expectException(IncompleteDsnException::class);
+        $factory->create(Dsn::fromString(sprintf('telegram://%s@%s/?channel=%s', 'simpleToken', 'testHost', 'testChannel')));
+    }
+
+    public function testCreateWithNoTokenThrowsMalformed(): void
+    {
+        $factory = new TelegramTransportFactory();
+
+        $this->expectException(IncompleteDsnException::class);
+        $factory->create(Dsn::fromString(sprintf('telegram://%s/?channel=%s', 'testHost', 'testChannel')));
+    }
+
+    public function testSupportsTelegramScheme(): void
+    {
+        $factory = new TelegramTransportFactory();
+
+        $this->assertTrue($factory->supports(Dsn::fromString('telegram://host/?channel=testChannel')));
+        $this->assertFalse($factory->supports(Dsn::fromString('somethingElse://host/?channel=testChannel')));
+    }
+
+    public function testNonTelegramSchemeThrows(): void
+    {
+        $factory = new TelegramTransportFactory();
+
+        $this->expectException(UnsupportedSchemeException::class);
+        $factory->create(Dsn::fromString('somethingElse://user:pwd@host/?channel=testChannel'));
+    }
+}
diff --git a/src/Symfony/Component/Notifier/Bridge/Telegram/Tests/TelegramTransportTest.php b/src/Symfony/Component/Notifier/Bridge/Telegram/Tests/TelegramTransportTest.php
new file mode 100644
index 0000000000000..352b390ffd00b
--- /dev/null
+++ b/src/Symfony/Component/Notifier/Bridge/Telegram/Tests/TelegramTransportTest.php
@@ -0,0 +1,138 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\Notifier\Bridge\Telegram\Tests;
+
+use PHPUnit\Framework\TestCase;
+use Symfony\Component\HttpClient\MockHttpClient;
+use Symfony\Component\Notifier\Bridge\Telegram\TelegramTransport;
+use Symfony\Component\Notifier\Exception\LogicException;
+use Symfony\Component\Notifier\Exception\TransportException;
+use Symfony\Component\Notifier\Message\ChatMessage;
+use Symfony\Component\Notifier\Message\MessageInterface;
+use Symfony\Component\Notifier\Message\MessageOptionsInterface;
+use Symfony\Contracts\HttpClient\HttpClientInterface;
+use Symfony\Contracts\HttpClient\ResponseInterface;
+
+final class TelegramTransportTest extends TestCase
+{
+    public function testToStringContainsProperties(): void
+    {
+        $channel = 'testChannel';
+
+        $transport = new TelegramTransport('testToken', $channel, $this->createMock(HttpClientInterface::class));
+        $transport->setHost('testHost');
+
+        $this->assertSame(sprintf('telegram://%s?channel=%s', 'testHost', $channel), (string) $transport);
+    }
+
+    public function testSupportsChatMessage(): void
+    {
+        $transport = new TelegramTransport('testToken', 'testChannel', $this->createMock(HttpClientInterface::class));
+
+        $this->assertTrue($transport->supports(new ChatMessage('testChatMessage')));
+        $this->assertFalse($transport->supports($this->createMock(MessageInterface::class)));
+    }
+
+    public function testSendNonChatMessageThrows(): void
+    {
+        $this->expectException(LogicException::class);
+        $transport = new TelegramTransport('testToken', 'testChannel', $this->createMock(HttpClientInterface::class));
+
+        $transport->send($this->createMock(MessageInterface::class));
+    }
+
+    public function testSendWithErrorResponseThrows(): void
+    {
+        $this->expectException(TransportException::class);
+        $this->expectExceptionMessageRegExp('/testDescription.+testErrorCode/');
+
+        $response = $this->createMock(ResponseInterface::class);
+        $response->expects($this->exactly(2))
+            ->method('getStatusCode')
+            ->willReturn(400);
+        $response->expects($this->once())
+            ->method('getContent')
+            ->willReturn(json_encode(['description' => 'testDescription', 'error_code' => 'testErrorCode']));
+
+        $client = new MockHttpClient(static function () use ($response): ResponseInterface {
+            return $response;
+        });
+
+        $transport = new TelegramTransport('testToken', 'testChannel', $client);
+
+        $transport->send(new ChatMessage('testMessage'));
+    }
+
+    public function testSendWithOptions(): void
+    {
+        $channel = 'testChannel';
+
+        $response = $this->createMock(ResponseInterface::class);
+        $response->expects($this->exactly(2))
+            ->method('getStatusCode')
+            ->willReturn(200);
+        $response->expects($this->once())
+            ->method('getContent')
+            ->willReturn('');
+
+        $expectedBody = [
+            'chat_id' => $channel,
+            'text' => 'testMessage',
+            'parse_mode' => 'Markdown',
+        ];
+
+        $client = new MockHttpClient(function (string $method, string $url, array $options = []) use ($response, $expectedBody): ResponseInterface {
+            $this->assertEquals($expectedBody, json_decode($options['body'], true));
+
+            return $response;
+        });
+
+        $transport = new TelegramTransport('testToken', $channel, $client);
+
+        $transport->send(new ChatMessage('testMessage'));
+    }
+
+    public function testSendWithChannelOverride(): void
+    {
+        $channelOverride = 'channelOverride';
+
+        $response = $this->createMock(ResponseInterface::class);
+        $response->expects($this->exactly(2))
+            ->method('getStatusCode')
+            ->willReturn(200);
+        $response->expects($this->once())
+            ->method('getContent')
+            ->willReturn('');
+
+        $expectedBody = [
+            'chat_id' => $channelOverride,
+            'text' => 'testMessage',
+            'parse_mode' => 'Markdown',
+        ];
+
+        $client = new MockHttpClient(function (string $method, string $url, array $options = []) use ($response, $expectedBody): ResponseInterface {
+            $this->assertEquals($expectedBody, json_decode($options['body'], true));
+
+            return $response;
+        });
+
+        $transport = new TelegramTransport('testToken', 'defaultChannel', $client);
+
+        $messageOptions = $this->createMock(MessageOptionsInterface::class);
+        $messageOptions
+            ->expects($this->once())
+            ->method('getRecipientId')
+            ->willReturn($channelOverride);
+
+        $transport->send(new ChatMessage('testMessage', $messageOptions));
+    }
+}
diff --git a/src/Symfony/Component/Notifier/Bridge/Telegram/composer.json b/src/Symfony/Component/Notifier/Bridge/Telegram/composer.json
index a562f74dce549..003215dd49e9a 100644
--- a/src/Symfony/Component/Notifier/Bridge/Telegram/composer.json
+++ b/src/Symfony/Component/Notifier/Bridge/Telegram/composer.json
@@ -20,6 +20,9 @@
         "symfony/http-client": "^4.3|^5.0",
         "symfony/notifier": "~5.0.0"
     },
+    "require-dev": {
+        "symfony/event-dispatcher": "^4.3|^5.0"
+    },
     "autoload": {
         "psr-4": { "Symfony\\Component\\Notifier\\Bridge\\Telegram\\": "" },
         "exclude-from-classmap": [