diff --git a/phpBB/phpbb/composer/io/translate_composer_trait.php b/phpBB/phpbb/composer/io/translate_composer_trait.php
index 09cc76fa8e..56a996d91c 100644
--- a/phpBB/phpbb/composer/io/translate_composer_trait.php
+++ b/phpBB/phpbb/composer/io/translate_composer_trait.php
@@ -28,7 +28,7 @@ trait translate_composer_trait
 	/**
 	 * @var array
 	 */
-	protected $composer_error;
+	protected $composer_error = [];
 
 	/**
 	 * {@inheritdoc}