constants.php will be loaded from the environment specific config folder if available.
diff --git a/system/core/CodeIgniter.php b/system/core/CodeIgniter.php
index 99c261e..39a4d7f 100644
--- a/system/core/CodeIgniter.php
+++ b/system/core/CodeIgniter.php
@@ -53,7 +53,14 @@
  *  Load the framework constants
  * ------------------------------------------------------
  */
-	require(APPPATH.'config/constants'.EXT);
+	if (file_exists(APPPATH.'config/'.ENVIRONMENT.'/constants'.EXT))
+	{
+		require(APPPATH.'config/'.ENVIRONMENT.'/constants'.EXT);
+	}
+	else
+	{
+		require(APPPATH.'config/constants'.EXT);
+	}
 
 /*
  * ------------------------------------------------------
@@ -365,4 +372,4 @@
 
 
 /* End of file CodeIgniter.php */
-/* Location: ./system/core/CodeIgniter.php */
+/* Location: ./system/core/CodeIgniter.php */
\ No newline at end of file
diff --git a/user_guide/changelog.html b/user_guide/changelog.html
index ea5134a..003daf3 100644
--- a/user_guide/changelog.html
+++ b/user_guide/changelog.html
@@ -59,6 +59,18 @@
 
 <p>The <img src="images/reactor-bullet.png" width="16" height="16" alt="Reactor Marker" /> indicates items that were contributed to CodeIgniter via CodeIgniter Reactor.</p>
 
+<h2>Version 2.0.2</h2>
+<p>Release Date: n/a<br />
+Hg Tag: n/a</p>
+
+<ul>
+	<li>General changes
+		<ul>
+			<li class="reactor"><kbd>constants.php</kbd> will now be loaded from the environment folder if available.</li>
+		</ul>
+	</li>
+</ul>
+
 <h2>Version 2.0.1</h2>
 <p>Release Date: March, 15, 2011<br />
 Hg Tag: v2.0.1</p>
@@ -68,7 +80,7 @@
 		<ul>
 			<li>Added <kbd>$config['cookie_secure']</kbd> to the config file to allow requiring a secure (HTTPS) in order to set cookies.</li>
 			<li class="reactor">Added the constant <kbd>CI_CORE</kbd> to help differentiate between Core: TRUE and Reactor: FALSE.</li>
-			<li class="reactor">Added an <kbd>ENVIRONMENT</kbd> constant in index.php, which affects PHP error reporting settings, and optionally, 
+			<li class="reactor">Added an <kbd>ENVIRONMENT</kbd> constant in index.php, which affects PHP error reporting settings, and optionally,
                 which configuration files are loaded (see below). Read more on the <a href="general/environments.html">Handling Environments</a> page.</li>
 			<li class="reactor">Added support for <a href="libraries/config.html#environments">environment-specific</a> configuration files.</li>
 		</ul>