diff --git a/phpBB/phpbb/composer/exception/managed_with_clean_error_exception.php b/phpBB/phpbb/composer/exception/managed_with_clean_error_exception.php
index 22addce1b7..f7f6d163db 100644
--- a/phpBB/phpbb/composer/exception/managed_with_clean_error_exception.php
+++ b/phpBB/phpbb/composer/exception/managed_with_clean_error_exception.php
@@ -29,7 +29,7 @@ class managed_with_clean_error_exception extends managed_with_error_exception
 	 */
 	public function __construct($prefix, $message = '', array $parameters = [], \Exception $previous = null, $code = 0)
 	{
-		parent::__construct($prefix . $message, $parameters, $previous, $code);
+		parent::__construct($prefix, $message, $parameters, $previous, $code);
 	}
 
 }
diff --git a/phpBB/phpbb/composer/exception/managed_with_enable_error_exception.php b/phpBB/phpbb/composer/exception/managed_with_enable_error_exception.php
index f9b3ce571b..eace036aed 100644
--- a/phpBB/phpbb/composer/exception/managed_with_enable_error_exception.php
+++ b/phpBB/phpbb/composer/exception/managed_with_enable_error_exception.php
@@ -29,7 +29,7 @@ class managed_with_enable_error_exception extends managed_with_error_exception
 	 */
 	public function __construct($prefix, $message = '', array $parameters = [], \Exception $previous = null, $code = 0)
 	{
-		parent::__construct($prefix . $message, $parameters, $previous, $code);
+		parent::__construct($prefix, $message, $parameters, $previous, $code);
 	}
 
 }
diff --git a/phpBB/phpbb/composer/exception/managed_with_error_exception.php b/phpBB/phpbb/composer/exception/managed_with_error_exception.php
index 2ea4600cf6..0ebb1e1adf 100644
--- a/phpBB/phpbb/composer/exception/managed_with_error_exception.php
+++ b/phpBB/phpbb/composer/exception/managed_with_error_exception.php
@@ -29,7 +29,6 @@ class managed_with_error_exception extends runtime_exception
 	 */
 	public function __construct($prefix, $message = '', array $parameters = [], \Exception $previous = null, $code = 0)
 	{
-		parent::__construct($prefix . $message, $parameters, $previous, $code);
+		parent::__construct($prefix, $message, $parameters, $previous, $code);
 	}
-
 }
diff --git a/phpBB/phpbb/composer/extension_manager.php b/phpBB/phpbb/composer/extension_manager.php
index f9d5ddb956..1e14a7591d 100644
--- a/phpBB/phpbb/composer/extension_manager.php
+++ b/phpBB/phpbb/composer/extension_manager.php
@@ -29,7 +29,7 @@ use phpbb\filesystem\filesystem;
 class extension_manager extends manager
 {
 	/**
-	 * @var manager
+	 * @var ext_manager
 	 */
 	protected $extension_manager;
 
@@ -102,7 +102,8 @@ class extension_manager extends manager
 	{
 		if ($this->enable_on_install)
 		{
-			$io->writeError([['ENABLING_EXTENSIONS', [], 1]], true);
+			/** @psalm-suppress InvalidArgument */
+			$io->writeError([['ENABLING_EXTENSIONS', [], 1]]);
 			foreach ($packages as $package => $version)
 			{
 				try
@@ -111,11 +112,13 @@ class extension_manager extends manager
 				}
 				catch (\phpbb\exception\runtime_exception $e)
 				{
-					$io->writeError([[$e->getMessage(), $e->get_parameters(), 4]], true);
+					/** @psalm-suppress InvalidArgument */
+					$io->writeError([[$e->getMessage(), $e->get_parameters(), 4]]);
 				}
 				catch (\Exception $e)
 				{
-					$io->writeError([[$e->getMessage(), [], 4]], true);
+					/** @psalm-suppress InvalidArgument */
+					$io->writeError([[$e->getMessage(), [], 4]]);
 				}
 			}
 		}
@@ -126,7 +129,8 @@ class extension_manager extends manager
 	 */
 	protected function pre_update(array $packages, IOInterface $io = null)
 	{
-		$io->writeError([['DISABLING_EXTENSIONS', [], 1]], true);
+		/** @psalm-suppress InvalidArgument */
+		$io->writeError([['DISABLING_EXTENSIONS', [], 1]]);
 		$this->enabled_extensions = [];
 		foreach ($packages as $package => $version)
 		{
@@ -140,11 +144,13 @@ class extension_manager extends manager
 			}
 			catch (\phpbb\exception\runtime_exception $e)
 			{
-				$io->writeError([[$e->getMessage(), $e->get_parameters(), 4]], true);
+				/** @psalm-suppress InvalidArgument */
+				$io->writeError([[$e->getMessage(), $e->get_parameters(), 4]]);
 			}
 			catch (\Exception $e)
 			{
-				$io->writeError([[$e->getMessage(), [], 4]], true);
+				/** @psalm-suppress InvalidArgument */
+				$io->writeError([[$e->getMessage(), [], 4]]);
 			}
 		}
 	}
@@ -154,7 +160,8 @@ class extension_manager extends manager
 	 */
 	protected function post_update(array $packages, IOInterface $io = null)
 	{
-		$io->writeError([['ENABLING_EXTENSIONS', [], 1]], true);
+		/** @psalm-suppress InvalidArgument */
+		$io->writeError([['ENABLING_EXTENSIONS', [], 1]]);
 		foreach ($this->enabled_extensions as $package)
 		{
 			try
@@ -163,11 +170,13 @@ class extension_manager extends manager
 			}
 			catch (\phpbb\exception\runtime_exception $e)
 			{
-				$io->writeError([[$e->getMessage(), $e->get_parameters(), 4]], true);
+				/** @psalm-suppress InvalidArgument */
+				$io->writeError([[$e->getMessage(), $e->get_parameters(), 4]]);
 			}
 			catch (\Exception $e)
 			{
-				$io->writeError([[$e->getMessage(), [], 4]], true);
+				/** @psalm-suppress InvalidArgument */
+				$io->writeError([[$e->getMessage(), [], 4]]);
 			}
 		}
 	}
@@ -195,7 +204,8 @@ class extension_manager extends manager
 	{
 		if ($this->purge_on_remove)
 		{
-			$io->writeError([['DISABLING_EXTENSIONS', [], 1]], true);
+			/** @psalm-suppress InvalidArgument */
+			$io->writeError([['DISABLING_EXTENSIONS', [], 1]]);
 		}
 
 		foreach ($packages as $package => $version)
@@ -216,11 +226,13 @@ class extension_manager extends manager
 			}
 			catch (\phpbb\exception\runtime_exception $e)
 			{
-				$io->writeError([[$e->getMessage(), $e->get_parameters(), 4]], true);
+				/** @psalm-suppress InvalidArgument */
+				$io->writeError([[$e->getMessage(), $e->get_parameters(), 4]]);
 			}
 			catch (\Exception $e)
 			{
-				$io->writeError([[$e->getMessage(), [], 4]], true);
+				/** @psalm-suppress InvalidArgument */
+				$io->writeError([[$e->getMessage(), [], 4]]);
 			}
 		}
 	}
@@ -244,7 +256,8 @@ class extension_manager extends manager
 		if ($this->extension_manager->is_enabled($package))
 		{
 			$enabled = true;
-			$io->writeError([['DISABLING_EXTENSIONS', [], 1]], true);
+			/** @psalm-suppress InvalidArgument */
+			$io->writeError([['DISABLING_EXTENSIONS', [], 1]]);
 			$this->extension_manager->disable($package);
 		}
 
@@ -279,7 +292,8 @@ class extension_manager extends manager
 		{
 			try
 			{
-				$io->writeError([['ENABLING_EXTENSIONS', [], 1]], true);
+				/** @psalm-suppress InvalidArgument */
+				$io->writeError([['ENABLING_EXTENSIONS', [], 1]]);
 				$this->extension_manager->enable($package);
 			}
 			catch (\Exception $e)
diff --git a/phpBB/phpbb/composer/installer.php b/phpBB/phpbb/composer/installer.php
index 330540378d..354c7ead28 100644
--- a/phpBB/phpbb/composer/installer.php
+++ b/phpBB/phpbb/composer/installer.php
@@ -147,11 +147,11 @@ class installer
 	 * @param array $packages Packages to install.
 	 *        Each entry may be a name or an array associating a version constraint to a name
 	 * @param array $whitelist White-listed packages (packages that can be installed/updated/removed)
-	 * @param IOInterface|null $io IO object used for the output
+	 * @param io\io_interface|null $io IO object used for the output
 	 *
 	 * @throws runtime_exception
 	 */
-	protected function do_install(array $packages, $whitelist, IOInterface $io = null)
+	protected function do_install(array $packages, $whitelist, io\io_interface $io = null)
 	{
 		if (!$io)
 		{
diff --git a/phpBB/phpbb/composer/manager_interface.php b/phpBB/phpbb/composer/manager_interface.php
index 0cf6324661..d14abee8bc 100644
--- a/phpBB/phpbb/composer/manager_interface.php
+++ b/phpBB/phpbb/composer/manager_interface.php
@@ -57,11 +57,11 @@ interface manager_interface
 	/**
 	 * Tells whether or not a package is managed by Composer.
 	 *
-	 * @param string $packages Package name
+	 * @param string $package Package name
 	 *
 	 * @return bool
 	 */
-	public function is_managed($packages);
+	public function is_managed($package);
 
 	/**
 	 * Returns the list of managed packages for the current type