diff --git a/phpseclib/Crypt/Random.php b/phpseclib/Crypt/Random.php
index b7874ea11..6230a55e0 100644
--- a/phpseclib/Crypt/Random.php
+++ b/phpseclib/Crypt/Random.php
@@ -106,7 +106,7 @@ function crypt_random_string($length)
             }
             if ($fp !== true && $fp !== false) { // surprisingly faster than !is_bool() or is_resource()
                 $temp = fread($fp, $length);
-                if (strlen($temp) != $length) {
+                if (strlen($temp) == $length) {
                     return $temp;
                 }
             }