diff --git a/Useful-Functions-for-Plugin-and-Theme-Security.md b/Useful-Functions-for-Plugin-and-Theme-Security.md
index 7e02030..1b5b59c 100644
--- a/Useful-Functions-for-Plugin-and-Theme-Security.md
+++ b/Useful-Functions-for-Plugin-and-Theme-Security.md
@@ -50,12 +50,11 @@ function zip_only_contains_allowed_extensions($zip_path, array $allowed_extensio
 
     for ($i = 0; $i < $zip->numFiles; $i++) {
         $stat = $zip->statIndex( $i );
+        $ext = pathinfo($stat['name'], PATHINFO_EXTENSION);
     
     	// Skip folders name (but their content will be checked)
-    	if (substr($stat['name'], -1) === '/')
+    	if ($ext === '' && substr($stat['name'], -1) === '/')
             continue;
-        
-        $ext = pathinfo($stat['name'], PATHINFO_EXTENSION);
 
         //print_r( "{$stat['name']} => {$ext}" . PHP_EOL . "<br/>");