diff --git a/phpBB/phpbb/install/console/command/install/config/show.php b/phpBB/phpbb/install/console/command/install/config/show.php
index 58ad7397da..7daede1b04 100644
--- a/phpBB/phpbb/install/console/command/install/config/show.php
+++ b/phpBB/phpbb/install/console/command/install/config/show.php
@@ -18,6 +18,7 @@ use phpbb\install\installer_configuration;
 use phpbb\language\language;
 use Symfony\Component\Config\Definition\Exception\Exception;
 use Symfony\Component\Config\Definition\Processor;
+use Symfony\Component\Console\Command\Command;
 use Symfony\Component\Console\Input\InputArgument;
 use Symfony\Component\Console\Input\InputInterface;
 use Symfony\Component\Console\Output\OutputInterface;
@@ -90,7 +91,7 @@ class show extends \phpbb\console\command\command
 		{
 			$iohandler->add_error_message(array('MISSING_FILE', $config_file));
 
-			return 1;
+			return Command::FAILURE;
 		}
 
 		try
@@ -101,7 +102,7 @@ class show extends \phpbb\console\command\command
 		{
 			$iohandler->add_error_message('INVALID_YAML_FILE');
 
-			return 1;
+			return Command::FAILURE;
 		}
 
 		$processor = new Processor();
@@ -115,11 +116,11 @@ class show extends \phpbb\console\command\command
 		{
 			$iohandler->add_error_message('INVALID_CONFIGURATION', $e->getMessage());
 
-			return 1;
+			return Command::FAILURE;
 		}
 
 		$style->block(Yaml::dump(array('installer' => $config), 10, 4, true, false));
 
-		return 0;
+		return Command::SUCCESS;
 	}
 }
diff --git a/phpBB/phpbb/install/console/command/install/config/validate.php b/phpBB/phpbb/install/console/command/install/config/validate.php
index 0b8a28beaa..eb638ad387 100644
--- a/phpBB/phpbb/install/console/command/install/config/validate.php
+++ b/phpBB/phpbb/install/console/command/install/config/validate.php
@@ -18,6 +18,7 @@ use phpbb\install\installer_configuration;
 use phpbb\language\language;
 use Symfony\Component\Config\Definition\Exception\Exception;
 use Symfony\Component\Config\Definition\Processor;
+use Symfony\Component\Console\Command\Command;
 use Symfony\Component\Console\Input\InputArgument;
 use Symfony\Component\Console\Input\InputInterface;
 use Symfony\Component\Console\Output\OutputInterface;
@@ -90,7 +91,7 @@ class validate extends \phpbb\console\command\command
 		{
 			$iohandler->add_error_message(array('MISSING_FILE', array($config_file)));
 
-			return 1;
+			return Command::FAILURE;
 		}
 
 		try
@@ -101,7 +102,7 @@ class validate extends \phpbb\console\command\command
 		{
 			$iohandler->add_error_message('INVALID_YAML_FILE');
 
-			return 1;
+			return Command::FAILURE;
 		}
 
 		$processor = new Processor();
@@ -115,10 +116,10 @@ class validate extends \phpbb\console\command\command
 		{
 			$iohandler->add_error_message('INVALID_CONFIGURATION', $e->getMessage());
 
-			return 1;
+			return Command::FAILURE;
 		}
 
 		$iohandler->add_success_message('CONFIGURATION_VALID');
-		return 0;
+		return Command::SUCCESS;
 	}
 }
diff --git a/phpBB/phpbb/install/console/command/install/install.php b/phpBB/phpbb/install/console/command/install/install.php
index e50eeeb5bc..1ad4ea8114 100644
--- a/phpBB/phpbb/install/console/command/install/install.php
+++ b/phpBB/phpbb/install/console/command/install/install.php
@@ -22,6 +22,7 @@ use phpbb\install\installer_configuration;
 use phpbb\language\language;
 use Symfony\Component\Config\Definition\Exception\Exception;
 use Symfony\Component\Config\Definition\Processor;
+use Symfony\Component\Console\Command\Command;
 use Symfony\Component\Console\Input\InputArgument;
 use Symfony\Component\Console\Input\InputInterface;
 use Symfony\Component\Console\Output\OutputInterface;
@@ -111,14 +112,14 @@ class install extends \phpbb\console\command\command
 		{
 			$iohandler->add_error_message('INSTALL_PHPBB_INSTALLED');
 
-			return 1;
+			return Command::FAILURE;
 		}
 
 		if (!is_file($config_file))
 		{
 			$iohandler->add_error_message(array('MISSING_FILE', $config_file));
 
-			return 1;
+			return Command::FAILURE;
 		}
 
 		try
@@ -129,7 +130,7 @@ class install extends \phpbb\console\command\command
 		{
 			$iohandler->add_error_message(array('INVALID_YAML_FILE', $config_file));
 
-			return 1;
+			return Command::FAILURE;
 		}
 
 		$processor = new Processor();
@@ -143,7 +144,7 @@ class install extends \phpbb\console\command\command
 		{
 			$iohandler->add_error_message('INVALID_CONFIGURATION', $e->getMessage());
 
-			return 1;
+			return Command::FAILURE;
 		}
 
 		$this->register_configuration($iohandler, $config);
@@ -151,12 +152,12 @@ class install extends \phpbb\console\command\command
 		try
 		{
 			$this->installer->run();
-			return 0;
+			return Command::SUCCESS;
 		}
 		catch (installer_exception $e)
 		{
 			$iohandler->add_error_message($e->getMessage());
-			return 1;
+			return Command::FAILURE;
 		}
 	}
 
diff --git a/phpBB/phpbb/install/console/command/update/config/show.php b/phpBB/phpbb/install/console/command/update/config/show.php
index 138c5cae28..df7a69ed31 100644
--- a/phpBB/phpbb/install/console/command/update/config/show.php
+++ b/phpBB/phpbb/install/console/command/update/config/show.php
@@ -18,6 +18,7 @@ use phpbb\install\updater_configuration;
 use phpbb\language\language;
 use Symfony\Component\Config\Definition\Exception\Exception;
 use Symfony\Component\Config\Definition\Processor;
+use Symfony\Component\Console\Command\Command;
 use Symfony\Component\Console\Input\InputArgument;
 use Symfony\Component\Console\Input\InputInterface;
 use Symfony\Component\Console\Output\OutputInterface;
@@ -90,7 +91,7 @@ class show extends \phpbb\console\command\command
 		{
 			$iohandler->add_error_message(array('MISSING_FILE', $config_file));
 
-			return 1;
+			return Command::FAILURE;
 		}
 
 		try
@@ -101,7 +102,7 @@ class show extends \phpbb\console\command\command
 		{
 			$iohandler->add_error_message('INVALID_YAML_FILE');
 
-			return 1;
+			return Command::FAILURE;
 		}
 
 		$processor = new Processor();
@@ -115,11 +116,11 @@ class show extends \phpbb\console\command\command
 		{
 			$iohandler->add_error_message('INVALID_CONFIGURATION', $e->getMessage());
 
-			return 1;
+			return Command::FAILURE;
 		}
 
 		$style->block(Yaml::dump(array('updater' => $config), 10, 4, true, false));
 
-		return 0;
+		return Command::SUCCESS;
 	}
 }
diff --git a/phpBB/phpbb/install/console/command/update/config/validate.php b/phpBB/phpbb/install/console/command/update/config/validate.php
index 8a0d963ac2..eb1a48546f 100644
--- a/phpBB/phpbb/install/console/command/update/config/validate.php
+++ b/phpBB/phpbb/install/console/command/update/config/validate.php
@@ -18,6 +18,7 @@ use phpbb\install\updater_configuration;
 use phpbb\language\language;
 use Symfony\Component\Config\Definition\Exception\Exception;
 use Symfony\Component\Config\Definition\Processor;
+use Symfony\Component\Console\Command\Command;
 use Symfony\Component\Console\Input\InputArgument;
 use Symfony\Component\Console\Input\InputInterface;
 use Symfony\Component\Console\Output\OutputInterface;
@@ -90,7 +91,7 @@ class validate extends \phpbb\console\command\command
 		{
 			$iohandler->add_error_message(array('MISSING_FILE', array($config_file)));
 
-			return 1;
+			return Command::FAILURE;
 		}
 
 		try
@@ -101,7 +102,7 @@ class validate extends \phpbb\console\command\command
 		{
 			$iohandler->add_error_message('INVALID_YAML_FILE');
 
-			return 1;
+			return Command::FAILURE;
 		}
 
 		$processor = new Processor();
@@ -115,10 +116,10 @@ class validate extends \phpbb\console\command\command
 		{
 			$iohandler->add_error_message('INVALID_CONFIGURATION', $e->getMessage());
 
-			return 1;
+			return Command::FAILURE;
 		}
 
 		$iohandler->add_success_message('CONFIGURATION_VALID');
-		return 0;
+		return Command::SUCCESS;
 	}
 }
diff --git a/phpBB/phpbb/install/console/command/update/update.php b/phpBB/phpbb/install/console/command/update/update.php
index d6e89b2477..f3320d358b 100644
--- a/phpBB/phpbb/install/console/command/update/update.php
+++ b/phpBB/phpbb/install/console/command/update/update.php
@@ -22,6 +22,7 @@ use phpbb\install\updater_configuration;
 use phpbb\language\language;
 use Symfony\Component\Config\Definition\Exception\Exception;
 use Symfony\Component\Config\Definition\Processor;
+use Symfony\Component\Console\Command\Command;
 use Symfony\Component\Console\Input\InputArgument;
 use Symfony\Component\Console\Input\InputInterface;
 use Symfony\Component\Console\Output\OutputInterface;
@@ -111,14 +112,14 @@ class update extends \phpbb\console\command\command
 		{
 			$iohandler->add_error_message('INSTALL_PHPBB_NOT_INSTALLED');
 
-			return 1;
+			return Command::FAILURE;
 		}
 
 		if (!is_file($config_file))
 		{
 			$iohandler->add_error_message(array('MISSING_FILE', $config_file));
 
-			return 1;
+			return Command::FAILURE;
 		}
 
 		try
@@ -129,7 +130,7 @@ class update extends \phpbb\console\command\command
 		{
 			$iohandler->add_error_message(array('INVALID_YAML_FILE', $config_file));
 
-			return 1;
+			return Command::FAILURE;
 		}
 
 		$processor = new Processor();
@@ -143,7 +144,7 @@ class update extends \phpbb\console\command\command
 		{
 			$iohandler->add_error_message('INVALID_CONFIGURATION', $e->getMessage());
 
-			return 1;
+			return Command::FAILURE;
 		}
 
 		$this->register_configuration($iohandler, $config);
@@ -151,12 +152,12 @@ class update extends \phpbb\console\command\command
 		try
 		{
 			$this->installer->run();
-			return 0;
+			return Command::SUCCESS;
 		}
 		catch (installer_exception $e)
 		{
 			$iohandler->add_error_message($e->getMessage());
-			return 1;
+			return Command::FAILURE;
 		}
 	}