diff --git a/lib/Cake/Utility/Security.php b/lib/Cake/Utility/Security.php
index 464d05f71..be128e64a 100644
--- a/lib/Cake/Utility/Security.php
+++ b/lib/Cake/Utility/Security.php
@@ -191,8 +191,10 @@ class Security {
 			E_USER_WARNING
 		);
 		$bytes = '';
-		while (strlen($bytes) < $length) {
+		$byteLength = 0;
+		while ($byteLength < $length) {
 			$bytes .= static::hash(CakeText::uuid() . uniqid(mt_rand(), true), 'sha512', true);
+			$byteLength = strlen($bytes);
 		}
 		return substr($bytes, 0, $length);
 	}