diff --git a/src/Symfony/Component/Uid/Command/GenerateUlidCommand.php b/src/Symfony/Component/Uid/Command/GenerateUlidCommand.php
index 2aa87e980466b..1f99b4f49c9a6 100644
--- a/src/Symfony/Component/Uid/Command/GenerateUlidCommand.php
+++ b/src/Symfony/Component/Uid/Command/GenerateUlidCommand.php
@@ -12,6 +12,8 @@
 namespace Symfony\Component\Uid\Command;
 
 use Symfony\Component\Console\Command\Command;
+use Symfony\Component\Console\Completion\CompletionInput;
+use Symfony\Component\Console\Completion\CompletionSuggestions;
 use Symfony\Component\Console\Input\InputInterface;
 use Symfony\Component\Console\Input\InputOption;
 use Symfony\Component\Console\Output\ConsoleOutputInterface;
@@ -83,14 +85,14 @@ protected function execute(InputInterface $input, OutputInterface $output)
             }
         }
 
-        switch ($input->getOption('format')) {
-            case 'base32': $format = 'toBase32'; break;
-            case 'base58': $format = 'toBase58'; break;
-            case 'rfc4122': $format = 'toRfc4122'; break;
-            default:
-                $io->error(sprintf('Invalid format "%s", did you mean "base32", "base58" or "rfc4122"?', $input->getOption('format')));
+        $formatOption = $input->getOption('format');
 
-                return 1;
+        if (\in_array($formatOption, $this->getAvailableFormatOptions())) {
+            $format = 'to'.ucfirst($formatOption);
+        } else {
+            $io->error(sprintf('Invalid format "%s", did you mean "base32", "base58" or "rfc4122"?', $input->getOption('format')));
+
+            return 1;
         }
 
         $count = (int) $input->getOption('count');
@@ -106,4 +108,20 @@ protected function execute(InputInterface $input, OutputInterface $output)
 
         return 0;
     }
+
+    public function complete(CompletionInput $input, CompletionSuggestions $suggestions): void
+    {
+        if ($input->mustSuggestOptionValuesFor('format')) {
+            $suggestions->suggestValues($this->getAvailableFormatOptions());
+        }
+    }
+
+    private function getAvailableFormatOptions(): array
+    {
+        return [
+            'base32',
+            'base58',
+            'rfc4122',
+        ];
+    }
 }
diff --git a/src/Symfony/Component/Uid/Command/GenerateUuidCommand.php b/src/Symfony/Component/Uid/Command/GenerateUuidCommand.php
index b6992151ec03d..d218b227aa7a4 100644
--- a/src/Symfony/Component/Uid/Command/GenerateUuidCommand.php
+++ b/src/Symfony/Component/Uid/Command/GenerateUuidCommand.php
@@ -12,6 +12,8 @@
 namespace Symfony\Component\Uid\Command;
 
 use Symfony\Component\Console\Command\Command;
+use Symfony\Component\Console\Completion\CompletionInput;
+use Symfony\Component\Console\Completion\CompletionSuggestions;
 use Symfony\Component\Console\Input\InputInterface;
 use Symfony\Component\Console\Input\InputOption;
 use Symfony\Component\Console\Output\ConsoleOutputInterface;
@@ -174,14 +176,14 @@ protected function execute(InputInterface $input, OutputInterface $output)
                 break;
         }
 
-        switch ($input->getOption('format')) {
-            case 'base32': $format = 'toBase32'; break;
-            case 'base58': $format = 'toBase58'; break;
-            case 'rfc4122': $format = 'toRfc4122'; break;
-            default:
-                $io->error(sprintf('Invalid format "%s", did you mean "base32", "base58" or "rfc4122"?', $input->getOption('format')));
+        $formatOption = $input->getOption('format');
+
+        if (\in_array($formatOption, $this->getAvailableFormatOptions())) {
+            $format = 'to'.ucfirst($formatOption);
+        } else {
+            $io->error(sprintf('Invalid format "%s", did you mean "base32", "base58" or "rfc4122"?', $formatOption));
 
-                return 1;
+            return 1;
         }
 
         $count = (int) $input->getOption('count');
@@ -197,4 +199,20 @@ protected function execute(InputInterface $input, OutputInterface $output)
 
         return 0;
     }
+
+    public function complete(CompletionInput $input, CompletionSuggestions $suggestions): void
+    {
+        if ($input->mustSuggestOptionValuesFor('format')) {
+            $suggestions->suggestValues($this->getAvailableFormatOptions());
+        }
+    }
+
+    private function getAvailableFormatOptions(): array
+    {
+        return [
+            'base32',
+            'base58',
+            'rfc4122',
+        ];
+    }
 }
diff --git a/src/Symfony/Component/Uid/Tests/Command/GenerateUlidCommandTest.php b/src/Symfony/Component/Uid/Tests/Command/GenerateUlidCommandTest.php
index 789a557107fe2..c304915ad73b0 100644
--- a/src/Symfony/Component/Uid/Tests/Command/GenerateUlidCommandTest.php
+++ b/src/Symfony/Component/Uid/Tests/Command/GenerateUlidCommandTest.php
@@ -12,6 +12,8 @@
 namespace Symfony\Component\Uid\Tests\Command;
 
 use PHPUnit\Framework\TestCase;
+use Symfony\Component\Console\Application;
+use Symfony\Component\Console\Tester\CommandCompletionTester;
 use Symfony\Component\Console\Tester\CommandTester;
 use Symfony\Component\Uid\Command\GenerateUlidCommand;
 use Symfony\Component\Uid\Ulid;
@@ -100,4 +102,24 @@ public function testUlidsAreDifferentWhenGeneratingSeveralNow()
 
         $this->assertNotSame($ulids[0], $ulids[1]);
     }
+
+    /**
+     * @dataProvider provideCompletionSuggestions
+     */
+    public function testComplete(array $input, array $expectedSuggestions)
+    {
+        $application = new Application();
+        $application->add(new GenerateUlidCommand());
+        $tester = new CommandCompletionTester($application->get('ulid:generate'));
+        $suggestions = $tester->complete($input, 2);
+        $this->assertSame($expectedSuggestions, $suggestions);
+    }
+
+    public function provideCompletionSuggestions(): iterable
+    {
+        yield 'option --format' => [
+            ['--format', ''],
+            ['base32', 'base58', 'rfc4122'],
+        ];
+    }
 }
diff --git a/src/Symfony/Component/Uid/Tests/Command/GenerateUuidCommandTest.php b/src/Symfony/Component/Uid/Tests/Command/GenerateUuidCommandTest.php
index 408fd47d31600..d95d2c4e0dba5 100644
--- a/src/Symfony/Component/Uid/Tests/Command/GenerateUuidCommandTest.php
+++ b/src/Symfony/Component/Uid/Tests/Command/GenerateUuidCommandTest.php
@@ -12,6 +12,8 @@
 namespace Symfony\Component\Uid\Tests\Command;
 
 use PHPUnit\Framework\TestCase;
+use Symfony\Component\Console\Application;
+use Symfony\Component\Console\Tester\CommandCompletionTester;
 use Symfony\Component\Console\Tester\CommandTester;
 use Symfony\Component\Uid\Command\GenerateUuidCommand;
 use Symfony\Component\Uid\Factory\UuidFactory;
@@ -229,4 +231,24 @@ public function testNamespacePredefinedKeyword()
 
         $this->assertSame('9c7d0eda-982d-5708-b4bd-79b3b179725d', (string) Uuid::fromRfc4122(trim($commandTester->getDisplay())));
     }
+
+    /**
+     * @dataProvider provideCompletionSuggestions
+     */
+    public function testComplete(array $input, array $expectedSuggestions)
+    {
+        $application = new Application();
+        $application->add(new GenerateUuidCommand());
+        $tester = new CommandCompletionTester($application->get('uuid:generate'));
+        $suggestions = $tester->complete($input, 2);
+        $this->assertSame($expectedSuggestions, $suggestions);
+    }
+
+    public function provideCompletionSuggestions(): iterable
+    {
+        yield 'option --format' => [
+            ['--format', ''],
+            ['base32', 'base58', 'rfc4122'],
+        ];
+    }
 }