diff --git a/crates/ptth_server/src/file_server.rs b/crates/ptth_server/src/file_server.rs
index e6786d4..3c13674 100644
--- a/crates/ptth_server/src/file_server.rs
+++ b/crates/ptth_server/src/file_server.rs
@@ -221,6 +221,8 @@ async fn serve_file (
 		response.header ("content-type".into (), b"application/javascript".to_vec ());
 	}
 	
+	response.header ("content-length".into (), content_length.to_string ().into_bytes ());
+	
 	response.content_length = Some (content_length);
 	
 	if let Some (body) = body {