diff --git a/src/Symfony/Component/Console/Command/CompleteCommand.php b/src/Symfony/Component/Console/Command/CompleteCommand.php
index 40006bd763d49..97357d6737ed3 100644
--- a/src/Symfony/Component/Console/Command/CompleteCommand.php
+++ b/src/Symfony/Component/Console/Command/CompleteCommand.php
@@ -31,16 +31,25 @@ final class CompleteCommand extends Command
     protected static $defaultName = '|_complete';
     protected static $defaultDescription = 'Internal command to provide shell completion suggestions';
 
-    private static $completionOutputs = [
-        'bash' => BashCompletionOutput::class,
-    ];
+    private $completionOutputs;
 
     private $isDebug = false;
 
+    /**
+     * @param array<string, class-string<CompletionOutputInterface>> $completionOutputs A list of additional completion outputs, with shell name as key and FQCN as value
+     */
+    public function __construct(array $completionOutputs = [])
+    {
+        // must be set before the parent constructor, as the property value is used in configure()
+        $this->completionOutputs = $completionOutputs + ['bash' => BashCompletionOutput::class];
+
+        parent::__construct();
+    }
+
     protected function configure(): void
     {
         $this
-            ->addOption('shell', 's', InputOption::VALUE_REQUIRED, 'The shell type (e.g. "bash")')
+            ->addOption('shell', 's', InputOption::VALUE_REQUIRED, 'The shell type ("'.implode('", "', array_keys($this->completionOutputs)).'")')
             ->addOption('input', 'i', InputOption::VALUE_REQUIRED | InputOption::VALUE_IS_ARRAY, 'An array of input tokens (e.g. COMP_WORDS or argv)')
             ->addOption('current', 'c', InputOption::VALUE_REQUIRED, 'The index of the "input" array that the cursor is in (e.g. COMP_CWORD)')
             ->addOption('symfony', 'S', InputOption::VALUE_REQUIRED, 'The version of the completion script')
@@ -71,8 +80,8 @@ protected function execute(InputInterface $input, OutputInterface $output): int
                 throw new \RuntimeException('The "--shell" option must be set.');
             }
 
-            if (!$completionOutput = self::$completionOutputs[$shell] ?? false) {
-                throw new \RuntimeException(sprintf('Shell completion is not supported for your shell: "%s" (supported: "%s").', $shell, implode('", "', array_keys(self::$completionOutputs))));
+            if (!$completionOutput = $this->completionOutputs[$shell] ?? false) {
+                throw new \RuntimeException(sprintf('Shell completion is not supported for your shell: "%s" (supported: "%s").', $shell, implode('", "', array_keys($this->completionOutputs))));
             }
 
             $completionInput = $this->createCompletionInput($input);
diff --git a/src/Symfony/Component/Console/Tests/Command/CompleteCommandTest.php b/src/Symfony/Component/Console/Tests/Command/CompleteCommandTest.php
index bf8ab00c9f246..189928897cc7c 100644
--- a/src/Symfony/Component/Console/Tests/Command/CompleteCommandTest.php
+++ b/src/Symfony/Component/Console/Tests/Command/CompleteCommandTest.php
@@ -17,6 +17,7 @@
 use Symfony\Component\Console\Command\CompleteCommand;
 use Symfony\Component\Console\Completion\CompletionInput;
 use Symfony\Component\Console\Completion\CompletionSuggestions;
+use Symfony\Component\Console\Completion\Output\BashCompletionOutput;
 use Symfony\Component\Console\Input\InputArgument;
 use Symfony\Component\Console\Output\OutputInterface;
 use Symfony\Component\Console\Tester\CommandTester;
@@ -50,6 +51,20 @@ public function testUnsupportedShellOption()
         $this->execute(['--shell' => 'unsupported']);
     }
 
+    public function testAdditionalShellSupport()
+    {
+        $this->command = new CompleteCommand(['supported' => BashCompletionOutput::class]);
+        $this->command->setApplication($this->application);
+        $this->tester = new CommandTester($this->command);
+
+        $this->execute(['--shell' => 'supported', '--current' => '1', '--input' => ['bin/console']]);
+
+        // verify that the default set of shells is still supported
+        $this->execute(['--shell' => 'bash', '--current' => '1', '--input' => ['bin/console']]);
+
+        $this->assertTrue(true);
+    }
+
     /**
      * @dataProvider provideInputAndCurrentOptionValues
      */
diff --git a/src/Symfony/Component/Console/Tests/Fixtures/application_1.json b/src/Symfony/Component/Console/Tests/Fixtures/application_1.json
index c346a44953a56..8c8ba2285f59a 100644
--- a/src/Symfony/Component/Console/Tests/Fixtures/application_1.json
+++ b/src/Symfony/Component/Console/Tests/Fixtures/application_1.json
@@ -89,7 +89,7 @@
                         "accept_value": true,
                         "is_value_required": true,
                         "is_multiple": false,
-                        "description": "The shell type (e.g. \"bash\")",
+                        "description": "The shell type (\"bash\")",
                         "default": null
                     },
                     "current": {
diff --git a/src/Symfony/Component/Console/Tests/Fixtures/application_1.xml b/src/Symfony/Component/Console/Tests/Fixtures/application_1.xml
index 0976d90abf81a..5a17229343fcf 100644
--- a/src/Symfony/Component/Console/Tests/Fixtures/application_1.xml
+++ b/src/Symfony/Component/Console/Tests/Fixtures/application_1.xml
@@ -10,7 +10,7 @@
       <arguments/>
       <options>
         <option name="--shell" shortcut="-s" accept_value="1" is_value_required="1" is_multiple="0">
-          <description>The shell type (e.g. "bash")</description>
+          <description>The shell type ("bash")</description>
           <defaults/>
         </option>
         <option name="--input" shortcut="-i" accept_value="1" is_value_required="1" is_multiple="1">
diff --git a/src/Symfony/Component/Console/Tests/Fixtures/application_2.json b/src/Symfony/Component/Console/Tests/Fixtures/application_2.json
index b56c9dd01092b..172eaa310fb44 100644
--- a/src/Symfony/Component/Console/Tests/Fixtures/application_2.json
+++ b/src/Symfony/Component/Console/Tests/Fixtures/application_2.json
@@ -93,7 +93,7 @@
                         "accept_value": true,
                         "is_value_required": true,
                         "is_multiple": false,
-                        "description": "The shell type (e.g. \"bash\")",
+                        "description": "The shell type (\"bash\")",
                         "default": null
                     },
                     "current": {
diff --git a/src/Symfony/Component/Console/Tests/Fixtures/application_2.xml b/src/Symfony/Component/Console/Tests/Fixtures/application_2.xml
index 5ccfe7e6887a9..cdd3d89437448 100644
--- a/src/Symfony/Component/Console/Tests/Fixtures/application_2.xml
+++ b/src/Symfony/Component/Console/Tests/Fixtures/application_2.xml
@@ -10,7 +10,7 @@
       <arguments/>
       <options>
         <option name="--shell" shortcut="-s" accept_value="1" is_value_required="1" is_multiple="0">
-          <description>The shell type (e.g. "bash")</description>
+          <description>The shell type ("bash")</description>
           <defaults/>
         </option>
         <option name="--input" shortcut="-i" accept_value="1" is_value_required="1" is_multiple="1">