See #2409: Avoid overwriting global $_SERVER and set Content-Type to protected property;
diff --git a/system/core/Input.php b/system/core/Input.php
index ff0bbe0..0ef8112 100644
--- a/system/core/Input.php
+++ b/system/core/Input.php
@@ -802,7 +802,7 @@
 			return $this->headers = apache_request_headers();
 		}
 
-		$_SERVER['HTTP_CONTENT_TYPE'] = isset($_SERVER['CONTENT_TYPE']) ? $_SERVER['CONTENT_TYPE'] : @getenv('CONTENT_TYPE');
+		$this->headers['Content-Type'] = isset($_SERVER['CONTENT_TYPE']) ? $_SERVER['CONTENT_TYPE'] : @getenv('CONTENT_TYPE');
 
 		foreach ($_SERVER as $key => $val)
 		{