diff --git a/src/Symfony/Component/Runtime/Tests/phpt/application.php b/src/Symfony/Component/Runtime/Tests/phpt/application.php
index 1e1014e9f3e5a..ca2de555edfb7 100644
--- a/src/Symfony/Component/Runtime/Tests/phpt/application.php
+++ b/src/Symfony/Component/Runtime/Tests/phpt/application.php
@@ -18,8 +18,10 @@
 
 return function (array $context) {
     $command = new Command('go');
-    $command->setCode(function (InputInterface $input, OutputInterface $output) use ($context) {
+    $command->setCode(function (InputInterface $input, OutputInterface $output) use ($context): int {
         $output->write('OK Application '.$context['SOME_VAR']);
+
+        return 0;
     });
 
     $app = new Application();
diff --git a/src/Symfony/Component/Runtime/Tests/phpt/command.php b/src/Symfony/Component/Runtime/Tests/phpt/command.php
index 3a5fa11e00000..e307d195b113e 100644
--- a/src/Symfony/Component/Runtime/Tests/phpt/command.php
+++ b/src/Symfony/Component/Runtime/Tests/phpt/command.php
@@ -19,7 +19,9 @@
 return function (Command $command, InputInterface $input, OutputInterface $output, array $context) {
     $command->addOption('hello', 'e', InputOption::VALUE_REQUIRED, 'How should I greet?', 'OK');
 
-    return $command->setCode(function () use ($input, $output, $context) {
+    return $command->setCode(function () use ($input, $output, $context): int {
         $output->write($input->getOption('hello').' Command '.$context['SOME_VAR']);
+
+        return 0;
     });
 };
diff --git a/src/Symfony/Component/Runtime/Tests/phpt/dotenv_overload_command_debug_exists_0_to_1.php b/src/Symfony/Component/Runtime/Tests/phpt/dotenv_overload_command_debug_exists_0_to_1.php
index af6409dda62bc..2968e37ea02f4 100644
--- a/src/Symfony/Component/Runtime/Tests/phpt/dotenv_overload_command_debug_exists_0_to_1.php
+++ b/src/Symfony/Component/Runtime/Tests/phpt/dotenv_overload_command_debug_exists_0_to_1.php
@@ -20,6 +20,8 @@
 
 require __DIR__.'/autoload.php';
 
-return static fn (Command $command, OutputInterface $output, array $context): Command => $command->setCode(static function () use ($output, $context): void {
+return static fn (Command $command, OutputInterface $output, array $context): Command => $command->setCode(static function () use ($output, $context): int {
     $output->writeln($context['DEBUG_ENABLED']);
+
+    return 0;
 });
diff --git a/src/Symfony/Component/Runtime/Tests/phpt/dotenv_overload_command_debug_exists_1_to_0.php b/src/Symfony/Component/Runtime/Tests/phpt/dotenv_overload_command_debug_exists_1_to_0.php
index 78a0bf29448b8..1f2fa3590e16f 100644
--- a/src/Symfony/Component/Runtime/Tests/phpt/dotenv_overload_command_debug_exists_1_to_0.php
+++ b/src/Symfony/Component/Runtime/Tests/phpt/dotenv_overload_command_debug_exists_1_to_0.php
@@ -20,6 +20,8 @@
 
 require __DIR__.'/autoload.php';
 
-return static fn (Command $command, OutputInterface $output, array $context): Command => $command->setCode(static function () use ($output, $context): void {
+return static fn (Command $command, OutputInterface $output, array $context): Command => $command->setCode(static function () use ($output, $context): int {
     $output->writeln($context['DEBUG_MODE']);
+
+    return 0;
 });
diff --git a/src/Symfony/Component/Runtime/Tests/phpt/dotenv_overload_command_env_exists.php b/src/Symfony/Component/Runtime/Tests/phpt/dotenv_overload_command_env_exists.php
index 3e72372e5af06..8587f20f2382b 100644
--- a/src/Symfony/Component/Runtime/Tests/phpt/dotenv_overload_command_env_exists.php
+++ b/src/Symfony/Component/Runtime/Tests/phpt/dotenv_overload_command_env_exists.php
@@ -20,6 +20,8 @@
 
 require __DIR__.'/autoload.php';
 
-return static fn (Command $command, OutputInterface $output, array $context): Command => $command->setCode(static function () use ($output, $context): void {
+return static fn (Command $command, OutputInterface $output, array $context): Command => $command->setCode(static function () use ($output, $context): int {
     $output->writeln($context['ENV_MODE']);
+
+    return 0;
 });
diff --git a/src/Symfony/Component/Runtime/Tests/phpt/dotenv_overload_command_no_debug.php b/src/Symfony/Component/Runtime/Tests/phpt/dotenv_overload_command_no_debug.php
index 3fe4f44d7967b..4ab7694298f95 100644
--- a/src/Symfony/Component/Runtime/Tests/phpt/dotenv_overload_command_no_debug.php
+++ b/src/Symfony/Component/Runtime/Tests/phpt/dotenv_overload_command_no_debug.php
@@ -19,6 +19,8 @@
 
 require __DIR__.'/autoload.php';
 
-return static fn (Command $command, OutputInterface $output, array $context): Command => $command->setCode(static function () use ($output, $context): void {
+return static fn (Command $command, OutputInterface $output, array $context): Command => $command->setCode(static function () use ($output, $context): int {
     $output->writeln($context['DEBUG_ENABLED']);
+
+    return 0;
 });