diff --git a/includes/ULSJsonMessageLoader.php b/includes/ULSJsonMessageLoader.php
index 18db38fb..fb425b8a 100644
--- a/includes/ULSJsonMessageLoader.php
+++ b/includes/ULSJsonMessageLoader.php
@@ -44,9 +44,7 @@ class ULSJsonMessageLoader {
 			$filenames[] = __DIR__ . "/../i18n/$language.json";
 		}
 
-		$filenames = array_filter( $filenames, function ( $filename ) {
-			return file_exists( $filename );
-		} );
+		$filenames = array_filter( $filenames, 'file_exists' );
 
 		return $filenames;
 	}