diff --git a/lib/openpgp_crypt_rsa.php b/lib/openpgp_crypt_rsa.php
index 472e74c..e6b5752 100644
--- a/lib/openpgp_crypt_rsa.php
+++ b/lib/openpgp_crypt_rsa.php
@@ -7,7 +7,7 @@
  */
 
 // From http://phpseclib.sourceforge.net/
-require 'Crypt/RSA.php';
+require_once 'Crypt/RSA.php';
 
 require_once dirname(__FILE__).'/openpgp.php';
 @include_once dirname(__FILE__).'/openpgp_crypt_symmetric.php'; /* For encrypt/decrypt */