diff --git a/phpBB/includes/json_response.php b/phpBB/includes/json_response.php
index 95d02e3c0e..dfddea98f2 100644
--- a/phpBB/includes/json_response.php
+++ b/phpBB/includes/json_response.php
@@ -30,7 +30,7 @@ class phpbb_json_response
 	 */
 	public function send($data, $exit = true)
 	{
-		header('Content-type: application/json');
+		header('Content-Type: application/json');
 		echo json_encode($data);
 
 		if ($exit)