diff --git a/phpseclib/File/X509.php b/phpseclib/File/X509.php
index 36a6287b..75579b5d 100644
--- a/phpseclib/File/X509.php
+++ b/phpseclib/File/X509.php
@@ -1612,6 +1612,10 @@ class File_X509
         if (is_array($extensions)) {
             $size = count($extensions);
             for ($i = 0; $i < $size; $i++) {
+                if (is_object($extensions[$i]) && strtolower(get_class($extensions[$i])) == 'file_asn1_element') {
+                    continue;
+                }
+
                 $id = $extensions[$i]['extnId'];
                 $value = &$extensions[$i]['extnValue'];