diff --git a/src/CardCreator.php b/src/CardCreator.php
index f05cdfd..7e52696 100644
--- a/src/CardCreator.php
+++ b/src/CardCreator.php
@@ -44,7 +44,6 @@ class CardCreator
 
         $number_of_keys = strlen($this->configration->keys);
         for ($i = 0; $i < $number_of_keys; $i++) {
-            $prefix = '$' . ($i+1);
             $equivalent = $chars[mt_rand(0, $char_count-1)];
 
             $equivalent = $this->escape($equivalent);