diff --git a/system/core/Common.php b/system/core/Common.php
index 341402c..2dd31d3 100644
--- a/system/core/Common.php
+++ b/system/core/Common.php
@@ -330,6 +330,24 @@
 
 // ------------------------------------------------------------------------
 
+if ( ! function_exists('is_https'))
+{
+	/**
+	 * Is HTTPS?
+	 *
+	 * Determines if the application is accessed via an encrypted
+	 * (HTTPS) connection.
+	 *
+	 * @return	bool
+	 */
+	function is_https()
+	{
+		return ( ! empty($_SERVER['HTTPS']) && strtolower($_SERVER['HTTPS']) !== 'off');
+	}
+}
+
+// ------------------------------------------------------------------------
+
 if ( ! function_exists('show_error'))
 {
 	/**
diff --git a/system/core/Config.php b/system/core/Config.php
index 8e4f998..e78128c 100644
--- a/system/core/Config.php
+++ b/system/core/Config.php
@@ -75,7 +75,7 @@
 		{
 			if (isset($_SERVER['HTTP_HOST']))
 			{
-				$base_url = ( ! empty($_SERVER['HTTPS']) && strtolower($_SERVER['HTTPS']) !== 'off') ? 'https' : 'http';
+				$base_url = is_https() ? 'https' : 'http';
 				$base_url .= '://'.$_SERVER['HTTP_HOST']
 					.str_replace(basename($_SERVER['SCRIPT_NAME']), '', $_SERVER['SCRIPT_NAME']);
 			}
diff --git a/system/core/Security.php b/system/core/Security.php
index b22d2cf..2fbc5b3 100644
--- a/system/core/Security.php
+++ b/system/core/Security.php
@@ -198,7 +198,7 @@
 		$expire = time() + $this->_csrf_expire;
 		$secure_cookie = (bool) config_item('cookie_secure');
 
-		if ($secure_cookie && (empty($_SERVER['HTTPS']) OR strtolower($_SERVER['HTTPS']) === 'off'))
+		if ($secure_cookie && ! is_https())
 		{
 			return FALSE;
 		}