diff --git a/phpseclib/File/X509.php b/phpseclib/File/X509.php
index 7740de7c..a95784b5 100644
--- a/phpseclib/File/X509.php
+++ b/phpseclib/File/X509.php
@@ -2417,7 +2417,7 @@ class X509
 
         $altName = [];
 
-        if (isset($subject->domains) && count($subject->domains) > 1) {
+        if (isset($subject->domains) && count($subject->domains)) {
             $altName = array_map(['\phpseclib\File\X509', 'dnsName'], $subject->domains);
         }