diff --git a/tailbone/static/js/tailbone.js b/tailbone/static/js/tailbone.js
index 4d2a01f1..bb7c0550 100644
--- a/tailbone/static/js/tailbone.js
+++ b/tailbone/static/js/tailbone.js
@@ -140,8 +140,9 @@ function timeout_warning_update() {
  * Warn user of impending session timeout.
  */
 function set_timeout_warning_timer() {
-    // TODO: are we calculating timer ok here?  (effective timeout - 60 seconds)
-    window.setTimeout(timeout_warning, session_timeout * 1000 - 60000);
+    // timout dialog says we're 60 seconds away, but we actually trigger when
+    // 70 seconds away from supposed timeout, in case of timer drift?
+    window.setTimeout(timeout_warning, session_timeout * 1000 - 70000);
 }