diff --git a/build/triple-dot-checker.php b/build/triple-dot-checker.php
index fa5edfcd5ee75..15985a0a95c4d 100644
--- a/build/triple-dot-checker.php
+++ b/build/triple-dot-checker.php
@@ -32,7 +32,7 @@
 	$it = new \RecursiveDirectoryIterator($dir);
 
 	foreach (new RecursiveIteratorIterator($it) as $file) {
-		if ($file->getExtension() === 'map') {
+		if (($file->getExtension() === 'map') || $file->isDir()) {
 			continue;
 		}
 		$content = file_get_contents($file->getPathname());