diff --git a/phpseclib/Crypt/RSA.php b/phpseclib/Crypt/RSA.php
index c5f69770..49a61f3b 100644
--- a/phpseclib/Crypt/RSA.php
+++ b/phpseclib/Crypt/RSA.php
@@ -3128,7 +3128,9 @@ class Crypt_RSA
         }
 
         // Compare
-        return $this->_equals($em, $em2) || $this->_equals($em, $em3);
+
+        return ($em2 !== false && $this->_equals($em, $em2)) ||
+               ($em3 !== false && $this->_equals($em, $em3));
     }
 
     /**