diff --git a/system/core/Common.php b/system/core/Common.php
index b87ce4d..85e18e4 100644
--- a/system/core/Common.php
+++ b/system/core/Common.php
@@ -355,7 +355,7 @@
 		{
 			return TRUE;
 		}
-		elseif (isset($_SERVER['HTTP_X_FORWARDED_PROTO']) && $_SERVER['HTTP_X_FORWARDED_PROTO'] === 'https')
+		elseif (isset($_SERVER['HTTP_X_FORWARDED_PROTO']) && strtolower($_SERVER['HTTP_X_FORWARDED_PROTO']) === 'https')
 		{
 			return TRUE;
 		}