diff --git a/classes/File.php b/classes/File.php
index 6cad978a70..145a01356c 100644
--- a/classes/File.php
+++ b/classes/File.php
@@ -71,7 +71,7 @@ class File extends Managed_DataObject
         );
     }
 
-    function isProtected($url) {
+    public static function isProtected($url) {
 
 		$protected_urls_exps = array(
 			'https://www.facebook.com/login.php',
@@ -674,4 +674,4 @@ class File extends Managed_DataObject
         echo "DONE.\n";
         echo "Resuming core schema upgrade...";
     }
-}
\ No newline at end of file
+}