diff --git a/src/Faker/Provider/Base.php b/src/Faker/Provider/Base.php
index ce7c6373..f0eeb0e2 100644
--- a/src/Faker/Provider/Base.php
+++ b/src/Faker/Provider/Base.php
@@ -141,7 +141,7 @@ class Base
      * @param  string $string String that should be converted to lowercase
      * @return string
      */
-    public static function toLower($string)
+    public static function toLower($string = '')
     {
         return extension_loaded('mbstring') ? mb_strtolower($string) : strtolower($string);
     }
@@ -152,7 +152,7 @@ class Base
      * @param  string $string String that should be converted to uppercase
      * @return string
      */
-    public static function toUpper($string)
+    public static function toUpper($string = '')
     {
         return extension_loaded('mbstring') ? mb_strtoupper($string) : strtoupper($string);
     }
diff --git a/test/documentor.php b/test/documentor.php
index af0a21c6..fb6c665b 100644
--- a/test/documentor.php
+++ b/test/documentor.php
@@ -11,5 +11,6 @@ $documentor = new Faker\Documentor($generator);
 
 <?php foreach ($formatters as $formatter => $example): ?>
     <?php echo str_pad($formatter, 23) ?><?php if ($example): ?> // <?php echo $example ?> <?php endif; ?>
+
 <?php endforeach; ?>
 <?php endforeach;