diff --git a/Caddyfile b/Caddyfile
index 00bc45b..e4e57f7 100644
--- a/Caddyfile
+++ b/Caddyfile
@@ -62,7 +62,7 @@
 	header @storage_preflight {
 		Access-Control-Allow-Origin "{http.request.header.Origin}"
 		Access-Control-Allow-Methods "GET, HEAD, PUT, POST, DELETE, OPTIONS"
-		Access-Control-Allow-Headers "*"
+		Access-Control-Allow-Headers "{http.request.header.Access-Control-Request-Headers}"
 		Access-Control-Max-Age "86400"
 	}
 	respond @storage_preflight 204
@@ -74,5 +74,9 @@
 
 	reverse_proxy localhost:3900 {
 		header_up X-Real-IP {http.request.header.X-Real-IP}
+		header_down -Access-Control-Allow-Origin
+		header_down -Access-Control-Allow-Methods
+		header_down -Access-Control-Allow-Headers
+		header_down -Access-Control-Expose-Headers
 	}
 }