diff --git a/system/helpers/form_helper.php b/system/helpers/form_helper.php
index d9305c0..8733ae0 100644
--- a/system/helpers/form_helper.php
+++ b/system/helpers/form_helper.php
@@ -65,7 +65,7 @@
 		$form .= '>';
 
 		// Add CSRF field if enabled, but leave it out for GET requests and requests to external websites	
-		if ($CI->config->item('csrf_protection') === TRUE AND ! (strpos($action, $CI->config->site_url()) === FALSE OR strpos($form, 'method="get"')))	
+		if ($CI->config->item('csrf_protection') === TRUE AND ! (strpos($action, $CI->config->base_url()) === FALSE OR strpos($form, 'method="get"')))	
 		{
 			$hidden[$CI->security->get_csrf_token_name()] = $CI->security->get_csrf_hash();
 		}
diff --git a/user_guide/changelog.html b/user_guide/changelog.html
index a20f279..ae66add 100644
--- a/user_guide/changelog.html
+++ b/user_guide/changelog.html
@@ -71,6 +71,7 @@
 <h3>Bug fixes for 2.1.1</h3>
 <ul>
 	<li>Fixed a bug (#697) - A wrong array key was used in the Upload library to check for mime-types.</li>
+	<li>Fixed a bug - form_open() compared $action against site_url() instead of base_url()</li>
 </ul>