diff --git a/quiz.js b/quiz.js
index 827f977afc6c860c8b2bf2ae6706616db8f7fc9d..4e81267cdf23117b595287faa7c1dd6f4fb271ba 100644
--- a/quiz.js
+++ b/quiz.js
@@ -2,7 +2,7 @@
 // ./LICENSE for more details.
 
 "use strict";
-const version = "$Id: quiz.js,v 1.16 2024/01/20 11:17:56 oj14ozun Exp oj14ozun $";
+const version = "$Id: quiz.js,v 1.17 2024/01/20 11:19:11 oj14ozun Exp oj14ozun $";
 
 const js_version  = document.getElementById("js-version");
 js_version.innerText = version;
@@ -25,6 +25,7 @@ const class_list  = document.documentElement.classList;
 
 // toggle information panel
 info_toggle.onclick = _ => class_list.toggle("open");
+info_toggle.onkeydown = ev => ev.keyCode != 13;
 
 // state variables
 var questions;                  // quiz data