diff --git a/src/Util/KeyAlgorithm/KeyAlgorithmInterface.php b/src/Util/KeyAlgorithm/KeyAlgorithmInterface.php
index ee970172..64c0ed3c 100644
--- a/src/Util/KeyAlgorithm/KeyAlgorithmInterface.php
+++ b/src/Util/KeyAlgorithm/KeyAlgorithmInterface.php
@@ -18,5 +18,5 @@ interface KeyAlgorithmInterface
      * @param  integer $len Length of the generated code
      * @return string
      */
-    public function generate();
+    public function generate($len);
 }