diff --git a/README.md b/README.md
index a217cdf..d2295d0 100644
--- a/README.md
+++ b/README.md
@@ -133,11 +133,12 @@ Revision history
 
 v0.5.x (latest)
 
+* Adding configuration item in `img_config.php` for setting valid characters in image filename.
+* Moving `webroot/test*` into directory `webroot/test`.
 * `webroot/check_system.php` now outputs if extension for exif is loaded.
 * Broke API when `initDimensions()` split into two methods, new `initDimensions()` and `loadImageDetails()`.
 * Added `autoRotate,`aro` to auto rotate image based on EXIF information.
 * Added `bgColor,`bgc` to use as backgroundcolor when needing a filler color, for example rotate 45.
-* Added `rotate,`r` as an alias to `rotateAfter`.
 * Added `rotateBefore,`rb` to rotate image a certain angle before processing.
 * Added `rotateAfter,`ra` to rotate image a certain angle after processing.
 * Cleaned up code formatting, removed trailing spaces.
diff --git a/webroot/img.php b/webroot/img.php
index b1ddd4f..05e8032 100644
--- a/webroot/img.php
+++ b/webroot/img.php
@@ -128,7 +128,7 @@ $verbose = getDefined(array('verbose', 'v'), true, false);
 $srcImage = get('src')
     or errorPage('Must set src-attribute.');
 
-preg_match('#^[a-z0-9A-Z-/_\.]+$#', $srcImage)
+preg_match($config['error_reporting'], $srcImage)
     or errorPage('Filename contains invalid characters.');
 
 verbose("src = $srcImage");
diff --git a/webroot/img_config.php b/webroot/img_config.php
index a6acfe5..bf5c8d6 100644
--- a/webroot/img_config.php
+++ b/webroot/img_config.php
@@ -17,6 +17,13 @@ return array(
 
 
 
+    /**
+     * Check image filename that it only contain valid characters.
+     */
+    'valid_filename' => '#^[a-z0-9A-Z-/_\.]+$#',
+
+
+
     /**
      * Set default timezone, it defaults to UTC if not specified otherwise.
      *