diff --git a/src/PHP_Compat_Command.php b/src/PHP_Compat_Command.php
index 0387f3e..03a442e 100644
--- a/src/PHP_Compat_Command.php
+++ b/src/PHP_Compat_Command.php
@@ -217,6 +217,7 @@ private static function scan_extension( $extension, $php_version ) {
 		$result = array(
 			'name'     => $extension['basename'],
 			'version'  => $extension['version'],
+			'files'    => '',
 		);
 		$descriptors = array(
 			0 => STDIN,