diff --git a/UPGRADE-6.1.md b/UPGRADE-6.1.md
index d48aca725b3f..825b2109f0c6 100644
--- a/UPGRADE-6.1.md
+++ b/UPGRADE-6.1.md
@@ -12,6 +12,8 @@ Console
 -------
 
  * Deprecate `Command::$defaultName` and `Command::$defaultDescription`, use the `AsCommand` attribute instead
+ * Add argument `$suggestedValues` to `Command::addArgument` and `Command::addOption`
+ * Add argument `$suggestedValues` to `InputArgument` and `InputOption` constructors
 
 HttpKernel
 ----------
diff --git a/src/Symfony/Component/Console/CHANGELOG.md b/src/Symfony/Component/Console/CHANGELOG.md
index 2573354f04c2..22c404363aa5 100644
--- a/src/Symfony/Component/Console/CHANGELOG.md
+++ b/src/Symfony/Component/Console/CHANGELOG.md
@@ -6,6 +6,7 @@ CHANGELOG
 
  * Add method `__toString()` to `InputInterface`
  * Deprecate `Command::$defaultName` and `Command::$defaultDescription`, use the `AsCommand` attribute instead
+ * Add suggested values for arguments and options in input definition, for input completion
 
 6.0
 ---
diff --git a/src/Symfony/Component/Console/Command/Command.php b/src/Symfony/Component/Console/Command/Command.php
index 147682e1e954..0a3f4b7889e5 100644
--- a/src/Symfony/Component/Console/Command/Command.php
+++ b/src/Symfony/Component/Console/Command/Command.php
@@ -15,6 +15,7 @@
 use Symfony\Component\Console\Attribute\AsCommand;
 use Symfony\Component\Console\Completion\CompletionInput;
 use Symfony\Component\Console\Completion\CompletionSuggestions;
+use Symfony\Component\Console\Completion\Suggestion;
 use Symfony\Component\Console\Exception\ExceptionInterface;
 use Symfony\Component\Console\Exception\InvalidArgumentException;
 use Symfony\Component\Console\Exception\LogicException;
@@ -319,6 +320,12 @@ public function run(InputInterface $input, OutputInterface $output): int
      */
     public function complete(CompletionInput $input, CompletionSuggestions $suggestions): void
     {
+        $definition = $this->getDefinition();
+        if (CompletionInput::TYPE_OPTION_VALUE === $input->getCompletionType() && $definition->hasOption($input->getCompletionName())) {
+            $definition->getOption($input->getCompletionName())->complete($input, $suggestions);
+        } elseif (CompletionInput::TYPE_ARGUMENT_VALUE === $input->getCompletionType() && $definition->hasArgument($input->getCompletionName())) {
+            $definition->getArgument($input->getCompletionName())->complete($input, $suggestions);
+        }
     }
 
     /**
@@ -427,17 +434,22 @@ public function getNativeDefinition(): InputDefinition
     /**
      * Adds an argument.
      *
-     * @param int|null $mode    The argument mode: InputArgument::REQUIRED or InputArgument::OPTIONAL
-     * @param mixed    $default The default value (for InputArgument::OPTIONAL mode only)
+     * @param $mode    The argument mode: InputArgument::REQUIRED or InputArgument::OPTIONAL
+     * @param $default The default value (for InputArgument::OPTIONAL mode only)
+     * @param array|\Closure(CompletionInput,CompletionSuggestions):list<string|Suggestion> $suggestedValues The values used for input completion
      *
      * @throws InvalidArgumentException When argument mode is not valid
      *
      * @return $this
      */
-    public function addArgument(string $name, int $mode = null, string $description = '', mixed $default = null): static
+    public function addArgument(string $name, int $mode = null, string $description = '', mixed $default = null, /*array|\Closure $suggestedValues = null*/): static
     {
-        $this->definition->addArgument(new InputArgument($name, $mode, $description, $default));
-        $this->fullDefinition?->addArgument(new InputArgument($name, $mode, $description, $default));
+        $suggestedValues = 5 <= \func_num_args() ? func_get_arg(4) : [];
+        if (!\is_array($suggestedValues) && !$suggestedValues instanceof \Closure) {
+            throw new \TypeError(sprintf('Argument 5 passed to "%s()" must be array or \Closure, "%s" given.', __METHOD__, get_debug_type($suggestedValues)));
+        }
+        $this->definition->addArgument(new InputArgument($name, $mode, $description, $default, $suggestedValues));
+        $this->fullDefinition?->addArgument(new InputArgument($name, $mode, $description, $default, $suggestedValues));
 
         return $this;
     }
@@ -448,15 +460,20 @@ public function addArgument(string $name, int $mode = null, string $description
      * @param $shortcut The shortcuts, can be null, a string of shortcuts delimited by | or an array of shortcuts
      * @param $mode     The option mode: One of the InputOption::VALUE_* constants
      * @param $default  The default value (must be null for InputOption::VALUE_NONE)
+     * @param array|\Closure(CompletionInput,CompletionSuggestions):list<string|Suggestion> $suggestedValues The values used for input completion
      *
      * @throws InvalidArgumentException If option mode is invalid or incompatible
      *
      * @return $this
      */
-    public function addOption(string $name, string|array $shortcut = null, int $mode = null, string $description = '', mixed $default = null): static
+    public function addOption(string $name, string|array $shortcut = null, int $mode = null, string $description = '', mixed $default = null, /*array|\Closure $suggestedValues = []*/): static
     {
-        $this->definition->addOption(new InputOption($name, $shortcut, $mode, $description, $default));
-        $this->fullDefinition?->addOption(new InputOption($name, $shortcut, $mode, $description, $default));
+        $suggestedValues = 6 <= \func_num_args() ? func_get_arg(5) : [];
+        if (!\is_array($suggestedValues) && !$suggestedValues instanceof \Closure) {
+            throw new \TypeError(sprintf('Argument 5 passed to "%s()" must be array or \Closure, "%s" given.', __METHOD__, get_debug_type($suggestedValues)));
+        }
+        $this->definition->addOption(new InputOption($name, $shortcut, $mode, $description, $default, $suggestedValues));
+        $this->fullDefinition?->addOption(new InputOption($name, $shortcut, $mode, $description, $default, $suggestedValues));
 
         return $this;
     }
diff --git a/src/Symfony/Component/Console/Command/DumpCompletionCommand.php b/src/Symfony/Component/Console/Command/DumpCompletionCommand.php
index d70c18374178..7597a9e2cc65 100644
--- a/src/Symfony/Component/Console/Command/DumpCompletionCommand.php
+++ b/src/Symfony/Component/Console/Command/DumpCompletionCommand.php
@@ -12,8 +12,6 @@
 namespace Symfony\Component\Console\Command;
 
 use Symfony\Component\Console\Attribute\AsCommand;
-use Symfony\Component\Console\Completion\CompletionInput;
-use Symfony\Component\Console\Completion\CompletionSuggestions;
 use Symfony\Component\Console\Input\InputArgument;
 use Symfony\Component\Console\Input\InputInterface;
 use Symfony\Component\Console\Input\InputOption;
@@ -39,12 +37,7 @@ final class DumpCompletionCommand extends Command
      */
     protected static $defaultDescription = 'Dump the shell completion script';
 
-    public function complete(CompletionInput $input, CompletionSuggestions $suggestions): void
-    {
-        if ($input->mustSuggestArgumentValuesFor('shell')) {
-            $suggestions->suggestValues($this->getSupportedShells());
-        }
-    }
+    private array $supportedShells;
 
     protected function configure()
     {
@@ -82,7 +75,7 @@ protected function configure()
     <info>eval "$(${fullCommand} completion bash)"</>
 EOH
             )
-            ->addArgument('shell', InputArgument::OPTIONAL, 'The shell type (e.g. "bash"), the value of the "$SHELL" env var will be used if this is not given')
+            ->addArgument('shell', InputArgument::OPTIONAL, 'The shell type (e.g. "bash"), the value of the "$SHELL" env var will be used if this is not given', null, $this->getSupportedShells(...))
             ->addOption('debug', null, InputOption::VALUE_NONE, 'Tail the completion debug log')
         ;
     }
@@ -135,7 +128,7 @@ private function tailDebugLog(string $commandName, OutputInterface $output): voi
      */
     private function getSupportedShells(): array
     {
-        return array_map(function ($f) {
+        return $this->supportedShells ??= array_map(function ($f) {
             return pathinfo($f, \PATHINFO_EXTENSION);
         }, glob(__DIR__.'/../Resources/completion.*'));
     }
diff --git a/src/Symfony/Component/Console/Command/HelpCommand.php b/src/Symfony/Component/Console/Command/HelpCommand.php
index ad4b813e44e4..f5ddd5204fae 100644
--- a/src/Symfony/Component/Console/Command/HelpCommand.php
+++ b/src/Symfony/Component/Console/Command/HelpCommand.php
@@ -11,8 +11,6 @@
 
 namespace Symfony\Component\Console\Command;
 
-use Symfony\Component\Console\Completion\CompletionInput;
-use Symfony\Component\Console\Completion\CompletionSuggestions;
 use Symfony\Component\Console\Descriptor\ApplicationDescription;
 use Symfony\Component\Console\Helper\DescriptorHelper;
 use Symfony\Component\Console\Input\InputArgument;
@@ -39,8 +37,12 @@ protected function configure()
         $this
             ->setName('help')
             ->setDefinition([
-                new InputArgument('command_name', InputArgument::OPTIONAL, 'The command name', 'help'),
-                new InputOption('format', null, InputOption::VALUE_REQUIRED, 'The output format (txt, xml, json, or md)', 'txt'),
+                new InputArgument('command_name', InputArgument::OPTIONAL, 'The command name', 'help', function () {
+                    return array_keys((new ApplicationDescription($this->getApplication()))->getCommands());
+                }),
+                new InputOption('format', null, InputOption::VALUE_REQUIRED, 'The output format (txt, xml, json, or md)', 'txt', function () {
+                    return (new DescriptorHelper())->getFormats();
+                }),
                 new InputOption('raw', null, InputOption::VALUE_NONE, 'To output raw command help'),
             ])
             ->setDescription('Display help for a command')
@@ -81,19 +83,4 @@ protected function execute(InputInterface $input, OutputInterface $output): int
 
         return 0;
     }
-
-    public function complete(CompletionInput $input, CompletionSuggestions $suggestions): void
-    {
-        if ($input->mustSuggestArgumentValuesFor('command_name')) {
-            $descriptor = new ApplicationDescription($this->getApplication());
-            $suggestions->suggestValues(array_keys($descriptor->getCommands()));
-
-            return;
-        }
-
-        if ($input->mustSuggestOptionValuesFor('format')) {
-            $helper = new DescriptorHelper();
-            $suggestions->suggestValues($helper->getFormats());
-        }
-    }
 }
diff --git a/src/Symfony/Component/Console/Command/LazyCommand.php b/src/Symfony/Component/Console/Command/LazyCommand.php
index b674a6387b32..cb4d7f245195 100644
--- a/src/Symfony/Component/Console/Command/LazyCommand.php
+++ b/src/Symfony/Component/Console/Command/LazyCommand.php
@@ -14,6 +14,7 @@
 use Symfony\Component\Console\Application;
 use Symfony\Component\Console\Completion\CompletionInput;
 use Symfony\Component\Console\Completion\CompletionSuggestions;
+use Symfony\Component\Console\Completion\Suggestion;
 use Symfony\Component\Console\Helper\HelperSet;
 use Symfony\Component\Console\Input\InputDefinition;
 use Symfony\Component\Console\Input\InputInterface;
@@ -108,16 +109,28 @@ public function getNativeDefinition(): InputDefinition
         return $this->getCommand()->getNativeDefinition();
     }
 
-    public function addArgument(string $name, int $mode = null, string $description = '', mixed $default = null): static
+    /**
+     * {@inheritdoc}
+     *
+     * @param array|\Closure(CompletionInput,CompletionSuggestions):list<string|Suggestion> $suggestedValues The values used for input completion
+     */
+    public function addArgument(string $name, int $mode = null, string $description = '', mixed $default = null, /*array|\Closure $suggestedValues = []*/): static
     {
-        $this->getCommand()->addArgument($name, $mode, $description, $default);
+        $suggestedValues = 5 <= \func_num_args() ? func_get_arg(4) : [];
+        $this->getCommand()->addArgument($name, $mode, $description, $default, $suggestedValues);
 
         return $this;
     }
 
-    public function addOption(string $name, string|array $shortcut = null, int $mode = null, string $description = '', mixed $default = null): static
+    /**
+     * {@inheritdoc}
+     *
+     * @param array|\Closure(CompletionInput,CompletionSuggestions):list<string|Suggestion> $suggestedValues The values used for input completion
+     */
+    public function addOption(string $name, string|array $shortcut = null, int $mode = null, string $description = '', mixed $default = null, /*array|\Closure $suggestedValues = []*/): static
     {
-        $this->getCommand()->addOption($name, $shortcut, $mode, $description, $default);
+        $suggestedValues = 6 <= \func_num_args() ? func_get_arg(5) : [];
+        $this->getCommand()->addOption($name, $shortcut, $mode, $description, $default, $suggestedValues);
 
         return $this;
     }
diff --git a/src/Symfony/Component/Console/Command/ListCommand.php b/src/Symfony/Component/Console/Command/ListCommand.php
index 5c7260fe4c07..420bdde28004 100644
--- a/src/Symfony/Component/Console/Command/ListCommand.php
+++ b/src/Symfony/Component/Console/Command/ListCommand.php
@@ -11,8 +11,6 @@
 
 namespace Symfony\Component\Console\Command;
 
-use Symfony\Component\Console\Completion\CompletionInput;
-use Symfony\Component\Console\Completion\CompletionSuggestions;
 use Symfony\Component\Console\Descriptor\ApplicationDescription;
 use Symfony\Component\Console\Helper\DescriptorHelper;
 use Symfony\Component\Console\Input\InputArgument;
@@ -35,9 +33,13 @@ protected function configure()
         $this
             ->setName('list')
             ->setDefinition([
-                new InputArgument('namespace', InputArgument::OPTIONAL, 'The namespace name'),
+                new InputArgument('namespace', InputArgument::OPTIONAL, 'The namespace name', null, function () {
+                    return array_keys((new ApplicationDescription($this->getApplication()))->getNamespaces());
+                }),
                 new InputOption('raw', null, InputOption::VALUE_NONE, 'To output raw command list'),
-                new InputOption('format', null, InputOption::VALUE_REQUIRED, 'The output format (txt, xml, json, or md)', 'txt'),
+                new InputOption('format', null, InputOption::VALUE_REQUIRED, 'The output format (txt, xml, json, or md)', 'txt', function () {
+                    return (new DescriptorHelper())->getFormats();
+                }),
                 new InputOption('short', null, InputOption::VALUE_NONE, 'To skip describing commands\' arguments'),
             ])
             ->setDescription('List commands')
@@ -77,19 +79,4 @@ protected function execute(InputInterface $input, OutputInterface $output): int
 
         return 0;
     }
-
-    public function complete(CompletionInput $input, CompletionSuggestions $suggestions): void
-    {
-        if ($input->mustSuggestArgumentValuesFor('namespace')) {
-            $descriptor = new ApplicationDescription($this->getApplication());
-            $suggestions->suggestValues(array_keys($descriptor->getNamespaces()));
-
-            return;
-        }
-
-        if ($input->mustSuggestOptionValuesFor('format')) {
-            $helper = new DescriptorHelper();
-            $suggestions->suggestValues($helper->getFormats());
-        }
-    }
 }
diff --git a/src/Symfony/Component/Console/Input/InputArgument.php b/src/Symfony/Component/Console/Input/InputArgument.php
index 143e4b10ae71..f87bf404e3ec 100644
--- a/src/Symfony/Component/Console/Input/InputArgument.php
+++ b/src/Symfony/Component/Console/Input/InputArgument.php
@@ -11,6 +11,10 @@
 
 namespace Symfony\Component\Console\Input;
 
+use Symfony\Component\Console\Command\Command;
+use Symfony\Component\Console\Completion\CompletionInput;
+use Symfony\Component\Console\Completion\CompletionSuggestions;
+use Symfony\Component\Console\Completion\Suggestion;
 use Symfony\Component\Console\Exception\InvalidArgumentException;
 use Symfony\Component\Console\Exception\LogicException;
 
@@ -28,6 +32,7 @@ class InputArgument
     private string $name;
     private int $mode;
     private string|int|bool|array|null|float $default;
+    private array|\Closure $suggestedValues;
     private string $description;
 
     /**
@@ -35,10 +40,11 @@ class InputArgument
      * @param int|null                         $mode        The argument mode: self::REQUIRED or self::OPTIONAL
      * @param string                           $description A description text
      * @param string|bool|int|float|array|null $default     The default value (for self::OPTIONAL mode only)
+     * @param array|\Closure(CompletionInput,CompletionSuggestions):list<string|Suggestion> $suggestedValues The values used for input completion
      *
      * @throws InvalidArgumentException When argument mode is not valid
      */
-    public function __construct(string $name, int $mode = null, string $description = '', string|bool|int|float|array $default = null)
+    public function __construct(string $name, int $mode = null, string $description = '', string|bool|int|float|array $default = null, \Closure|array $suggestedValues = [])
     {
         if (null === $mode) {
             $mode = self::OPTIONAL;
@@ -49,6 +55,7 @@ public function __construct(string $name, int $mode = null, string $description
         $this->name = $name;
         $this->mode = $mode;
         $this->description = $description;
+        $this->suggestedValues = $suggestedValues;
 
         $this->setDefault($default);
     }
@@ -111,6 +118,27 @@ public function getDefault(): string|bool|int|float|array|null
         return $this->default;
     }
 
+    public function hasCompletion(): bool
+    {
+        return [] !== $this->suggestedValues;
+    }
+
+    /**
+     * Adds suggestions to $suggestions for the current completion input.
+     *
+     * @see Command::complete()
+     */
+    public function complete(CompletionInput $input, CompletionSuggestions $suggestions): void
+    {
+        $values = $this->suggestedValues;
+        if ($values instanceof \Closure && !\is_array($values = $values($input))) {
+            throw new LogicException(sprintf('Closure for argument "%s" must return an array. Got "%s".', $this->name, get_debug_type($values)));
+        }
+        if ($values) {
+            $suggestions->suggestValues($values);
+        }
+    }
+
     /**
      * Returns the description text.
      */
diff --git a/src/Symfony/Component/Console/Input/InputOption.php b/src/Symfony/Component/Console/Input/InputOption.php
index f9d74a8961ce..5ea4a7f47e7e 100644
--- a/src/Symfony/Component/Console/Input/InputOption.php
+++ b/src/Symfony/Component/Console/Input/InputOption.php
@@ -11,6 +11,10 @@
 
 namespace Symfony\Component\Console\Input;
 
+use Symfony\Component\Console\Command\Command;
+use Symfony\Component\Console\Completion\CompletionInput;
+use Symfony\Component\Console\Completion\CompletionSuggestions;
+use Symfony\Component\Console\Completion\Suggestion;
 use Symfony\Component\Console\Exception\InvalidArgumentException;
 use Symfony\Component\Console\Exception\LogicException;
 
@@ -50,16 +54,18 @@ class InputOption
     private string|array|null $shortcut;
     private int $mode;
     private string|int|bool|array|null|float $default;
+    private array|\Closure $suggestedValues;
     private string $description;
 
     /**
      * @param string|array|null                $shortcut The shortcuts, can be null, a string of shortcuts delimited by | or an array of shortcuts
      * @param int|null                         $mode     The option mode: One of the VALUE_* constants
      * @param string|bool|int|float|array|null $default  The default value (must be null for self::VALUE_NONE)
+     * @param array|\Closure(CompletionInput,CompletionSuggestions):list<string|Suggestion> $suggestedValues The values used for input completion
      *
      * @throws InvalidArgumentException If option mode is invalid or incompatible
      */
-    public function __construct(string $name, string|array $shortcut = null, int $mode = null, string $description = '', string|bool|int|float|array $default = null)
+    public function __construct(string $name, string|array $shortcut = null, int $mode = null, string $description = '', string|bool|int|float|array $default = null, array|\Closure $suggestedValues = [])
     {
         if (str_starts_with($name, '--')) {
             $name = substr($name, 2);
@@ -96,7 +102,11 @@ public function __construct(string $name, string|array $shortcut = null, int $mo
         $this->shortcut = $shortcut;
         $this->mode = $mode;
         $this->description = $description;
+        $this->suggestedValues = $suggestedValues;
 
+        if ($suggestedValues && !$this->acceptValue()) {
+            throw new LogicException('Cannot set suggested values if the option does not accept a value.');
+        }
         if ($this->isArray() && !$this->acceptValue()) {
             throw new InvalidArgumentException('Impossible to have an option mode VALUE_IS_ARRAY if the option does not accept a value.');
         }
@@ -201,6 +211,27 @@ public function getDescription(): string
         return $this->description;
     }
 
+    public function hasCompletion(): bool
+    {
+        return [] !== $this->suggestedValues;
+    }
+
+    /**
+     * Adds suggestions to $suggestions for the current completion input.
+     *
+     * @see Command::complete()
+     */
+    public function complete(CompletionInput $input, CompletionSuggestions $suggestions): void
+    {
+        $values = $this->suggestedValues;
+        if ($values instanceof \Closure && !\is_array($values = $values($input))) {
+            throw new LogicException(sprintf('Closure for option "%s" must return an array. Got "%s".', $this->name, get_debug_type($values)));
+        }
+        if ($values) {
+            $suggestions->suggestValues($values);
+        }
+    }
+
     /**
      * Checks whether the given option equals this one.
      */
diff --git a/src/Symfony/Component/Console/Tests/Command/CommandTest.php b/src/Symfony/Component/Console/Tests/Command/CommandTest.php
index 1d0a383de7d8..6aca4e4383b0 100644
--- a/src/Symfony/Component/Console/Tests/Command/CommandTest.php
+++ b/src/Symfony/Component/Console/Tests/Command/CommandTest.php
@@ -88,6 +88,16 @@ public function testAddArgument()
         $this->assertTrue($command->getDefinition()->hasArgument('foo'), '->addArgument() adds an argument to the command');
     }
 
+    public function testAddArgumentFull()
+    {
+        $command = new \TestCommand();
+        $command->addArgument('foo', InputArgument::OPTIONAL, 'Description', 'default', ['a', 'b']);
+        $argument = $command->getDefinition()->getArgument('foo');
+        $this->assertSame('Description', $argument->getDescription());
+        $this->assertSame('default', $argument->getDefault());
+        $this->assertTrue($argument->hasCompletion());
+    }
+
     public function testAddOption()
     {
         $command = new \TestCommand();
@@ -96,6 +106,17 @@ public function testAddOption()
         $this->assertTrue($command->getDefinition()->hasOption('foo'), '->addOption() adds an option to the command');
     }
 
+    public function testAddOptionFull()
+    {
+        $command = new \TestCommand();
+        $command->addOption('foo', ['f'], InputOption::VALUE_OPTIONAL, 'Description', 'default', ['a', 'b']);
+        $option = $command->getDefinition()->getOption('foo');
+        $this->assertSame('f', $option->getShortcut());
+        $this->assertSame('Description', $option->getDescription());
+        $this->assertSame('default', $option->getDefault());
+        $this->assertTrue($option->hasCompletion());
+    }
+
     public function testSetHidden()
     {
         $command = new \TestCommand();
diff --git a/src/Symfony/Component/Console/Tests/Input/InputArgumentTest.php b/src/Symfony/Component/Console/Tests/Input/InputArgumentTest.php
index 39a3de5c6200..814cfe388c12 100644
--- a/src/Symfony/Component/Console/Tests/Input/InputArgumentTest.php
+++ b/src/Symfony/Component/Console/Tests/Input/InputArgumentTest.php
@@ -12,6 +12,10 @@
 namespace Symfony\Component\Console\Tests\Input;
 
 use PHPUnit\Framework\TestCase;
+use Symfony\Component\Console\Completion\CompletionInput;
+use Symfony\Component\Console\Completion\CompletionSuggestions;
+use Symfony\Component\Console\Completion\Suggestion;
+use Symfony\Component\Console\Exception\LogicException;
 use Symfony\Component\Console\Input\InputArgument;
 
 class InputArgumentTest extends TestCase
@@ -95,4 +99,33 @@ public function testSetDefaultWithArrayArgument()
         $argument = new InputArgument('foo', InputArgument::IS_ARRAY);
         $argument->setDefault('default');
     }
+
+    public function testCompleteArray()
+    {
+        $values = ['foo', 'bar'];
+        $argument = new InputArgument('foo', null, '', null, $values);
+        $this->assertTrue($argument->hasCompletion());
+        $suggestions = new CompletionSuggestions();
+        $argument->complete(new CompletionInput(), $suggestions);
+        $this->assertSame($values, array_map(fn (Suggestion $suggestion) => $suggestion->getValue(), $suggestions->getValueSuggestions()));
+    }
+
+    public function testCompleteClosure()
+    {
+        $values = ['foo', 'bar'];
+        $argument = new InputArgument('foo', null, '', null, fn (CompletionInput $input): array => $values);
+        $this->assertTrue($argument->hasCompletion());
+        $suggestions = new CompletionSuggestions();
+        $argument->complete(new CompletionInput(), $suggestions);
+        $this->assertSame($values, array_map(fn (Suggestion $suggestion) => $suggestion->getValue(), $suggestions->getValueSuggestions()));
+    }
+
+    public function testCompleteClosureReturnIncorrectType()
+    {
+        $this->expectException(LogicException::class);
+        $this->expectExceptionMessage('Closure for argument "foo" must return an array. Got "string".');
+
+        $argument = new InputArgument('foo', InputArgument::OPTIONAL, '', null, fn (CompletionInput $input) => 'invalid');
+        $argument->complete(new CompletionInput(), new CompletionSuggestions());
+    }
 }
diff --git a/src/Symfony/Component/Console/Tests/Input/InputOptionTest.php b/src/Symfony/Component/Console/Tests/Input/InputOptionTest.php
index 943bcf628c58..0b5271b324ae 100644
--- a/src/Symfony/Component/Console/Tests/Input/InputOptionTest.php
+++ b/src/Symfony/Component/Console/Tests/Input/InputOptionTest.php
@@ -12,6 +12,10 @@
 namespace Symfony\Component\Console\Tests\Input;
 
 use PHPUnit\Framework\TestCase;
+use Symfony\Component\Console\Completion\CompletionInput;
+use Symfony\Component\Console\Completion\CompletionSuggestions;
+use Symfony\Component\Console\Completion\Suggestion;
+use Symfony\Component\Console\Exception\LogicException;
 use Symfony\Component\Console\Input\InputOption;
 
 class InputOptionTest extends TestCase
@@ -194,4 +198,41 @@ public function testEquals()
         $option2 = new InputOption('foo', 'f', InputOption::VALUE_OPTIONAL, 'Some description');
         $this->assertFalse($option->equals($option2));
     }
+
+    public function testSuggestedValuesErrorIfNoValue()
+    {
+        $this->expectException(LogicException::class);
+        $this->expectExceptionMessage('Cannot set suggested values if the option does not accept a value.');
+
+        new InputOption('foo', null, InputOption::VALUE_NONE, '', null, ['foo']);
+    }
+
+    public function testCompleteArray()
+    {
+        $values = ['foo', 'bar'];
+        $option = new InputOption('foo', null, InputOption::VALUE_OPTIONAL, '', null, $values);
+        $this->assertTrue($option->hasCompletion());
+        $suggestions = new CompletionSuggestions();
+        $option->complete(new CompletionInput(), $suggestions);
+        $this->assertSame($values, array_map(fn (Suggestion $suggestion) => $suggestion->getValue(), $suggestions->getValueSuggestions()));
+    }
+
+    public function testCompleteClosure()
+    {
+        $values = ['foo', 'bar'];
+        $option = new InputOption('foo', null, InputOption::VALUE_OPTIONAL, '', null, fn (CompletionInput $input): array => $values);
+        $this->assertTrue($option->hasCompletion());
+        $suggestions = new CompletionSuggestions();
+        $option->complete(new CompletionInput(), $suggestions);
+        $this->assertSame($values, array_map(fn (Suggestion $suggestion) => $suggestion->getValue(), $suggestions->getValueSuggestions()));
+    }
+
+    public function testCompleteClosureReturnIncorrectType()
+    {
+        $this->expectException(LogicException::class);
+        $this->expectExceptionMessage('Closure for option "foo" must return an array. Got "string".');
+
+        $option = new InputOption('foo', null, InputOption::VALUE_OPTIONAL, '', null, fn (CompletionInput $input) => 'invalid');
+        $option->complete(new CompletionInput(), new CompletionSuggestions());
+    }
 }