diff --git a/.gitignore b/.gitignore
index fce10c34f..88e30178d 100644
--- a/.gitignore
+++ b/.gitignore
@@ -4,6 +4,7 @@
 /composer.phar
 /vendor
 /nbproject
+/tests/composer-test.phar
 .phpunit.result.cache
 phpunit.xml
 .vagrant
diff --git a/tests/Composer/Test/AllFunctionalTest.php b/tests/Composer/Test/AllFunctionalTest.php
index c5fa6fa93..7d6834431 100644
--- a/tests/Composer/Test/AllFunctionalTest.php
+++ b/tests/Composer/Test/AllFunctionalTest.php
@@ -94,6 +94,7 @@ class AllFunctionalTest extends TestCase
         }
 
         $this->assertFileExists(self::$pharPath);
+        copy(self::$pharPath, __DIR__.'/../../composer-test.phar');
     }
 
     /**
diff --git a/tests/Composer/Test/Command/SelfUpdateCommandTest.php b/tests/Composer/Test/Command/SelfUpdateCommandTest.php
new file mode 100644
index 000000000..d0b855563
--- /dev/null
+++ b/tests/Composer/Test/Command/SelfUpdateCommandTest.php
@@ -0,0 +1,96 @@
+<?php declare(strict_types=1);
+
+/*
+ * This file is part of Composer.
+ *
+ * (c) Nils Adermann <naderman@naderman.de>
+ *     Jordi Boggiano <j.boggiano@seld.be>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Composer\Test\Command;
+
+use Composer\Test\TestCase;
+
+/**
+ * @group slow
+ * @depends Composer\Test\AllFunctionalTest::testBuildPhar
+ */
+class SelfUpdateCommandTest extends TestCase
+{
+    /**
+     * @var string
+     */
+    private $prevArgv;
+
+    public function setUp(): void
+    {
+        parent::setUp();
+
+        $this->prevArgv = $_SERVER['argv'][0];
+        $dir = $this->initTempComposer();
+        copy(__DIR__.'/../../../composer-test.phar', $dir.'/composer.phar');
+        $_SERVER['argv'][0] = $dir.'/composer.phar';
+    }
+
+    public function tearDown(): void
+    {
+        parent::tearDown();
+
+        $_SERVER['argv'][0] = $this->prevArgv;
+    }
+
+    public function testSuccessfulUpdate(): void
+    {
+        $appTester = $this->getApplicationTester();
+        $appTester->run(['command' => 'self-update']);
+
+        $appTester->assertCommandIsSuccessful();
+        $this->assertStringContainsString('Upgrading to version', $appTester->getDisplay());
+    }
+
+    public function testUpdateToSpecificVersion(): void
+    {
+        $appTester = $this->getApplicationTester();
+        $appTester->run(['command' => 'self-update', 'version' => '2.4.0']);
+
+        $appTester->assertCommandIsSuccessful();
+        $this->assertStringContainsString('Upgrading to version 2.4.0', $appTester->getDisplay());
+    }
+
+    public function testUpdateWithInvalidOptionThrowsException(): void
+    {
+        $this->expectException(\InvalidArgumentException::class);
+        $this->expectExceptionMessage('The "invalid-option" argument does not exist.');
+
+        $appTester = $this->getApplicationTester();
+        $appTester->run(['command' => 'self-update', 'invalid-option' => true]);
+    }
+
+    /**
+     * @dataProvider channelOptions
+     */
+    public function testUpdateToDifferentChannel(string $option, string $expectedOutput): void
+    {
+        $appTester = $this->getApplicationTester();
+        $appTester->run(['command' => 'self-update', $option => true]);
+        $appTester->assertCommandIsSuccessful();
+
+        $this->assertStringContainsString('Upgrading to version', $appTester->getDisplay());
+        $this->assertStringContainsString($expectedOutput, $appTester->getDisplay());
+    }
+
+    /**
+     * @return array<array<string>>
+     */
+    public function channelOptions(): array
+    {
+        return [
+            ['--stable', 'stable channel'],
+            ['--preview', 'preview channel'],
+            ['--snapshot', 'snapshot channel'],
+        ];
+    }
+}