diff --git a/pkg/dmsgpty/ui.go b/pkg/dmsgpty/ui.go
index 8315f507..bcdc1ae8 100644
--- a/pkg/dmsgpty/ui.go
+++ b/pkg/dmsgpty/ui.go
@@ -136,7 +136,8 @@ func (ui *UI) Handler(customCommands map[string][]string) http.HandlerFunc {
 		}
 		defer func() { log.WithError(ws.Close(websocket.StatusNormalClosure, "closed")).Debug("Closed ws.") }()
 
-		wsConn := websocket.NetConn(r.Context(), ws, websocket.MessageText)
+		// Use binary mode for PTY data - text mode fails on non-UTF-8 bytes
+		wsConn := websocket.NetConn(r.Context(), ws, websocket.MessageBinary)
 
 		// open pty
 		logWS(wsConn, "Dialing...")
diff --git a/pkg/dmsgpty/ui_html.go b/pkg/dmsgpty/ui_html.go
index 841ca793..084efa10 100644
--- a/pkg/dmsgpty/ui_html.go
+++ b/pkg/dmsgpty/ui_html.go
@@ -4318,7 +4318,6 @@ func writeTermHTML(w io.Writer) (int64, error) {
 	if err != nil {
 		return 0, err
 	}
-	defer gz.Close() //nolint
 
-	return io.Copy(w, gz) //nolint:gosec // HTML is trusted content
+	return io.Copy(w, gz) //nolint:gosec // G110: embedded content is trusted
 }