diff --git a/app/functions.php b/app/functions.php
index ada96d97c..e5b2977be 100644
--- a/app/functions.php
+++ b/app/functions.php
@@ -6,7 +6,7 @@ function concat_files(array $files)
 {
     $data = '';
     foreach ($files as $pattern) {
-        foreach (glob($pattern) as $filename) {
+        foreach (glob($pattern, GLOB_ERR | GLOB_NOCHECK) as $filename) {
             echo $filename.PHP_EOL;
             if (! file_exists($filename)) {
                 die("$filename not found\n");