diff --git a/www/code/markers.js b/www/code/markers.js
index 326de8be0..bf3f00f82 100644
--- a/www/code/markers.js
+++ b/www/code/markers.js
@@ -46,7 +46,7 @@ define([
             inclusiveRight: uid === Env.myAuthorId,
             css: "background-color: " + rgba,
             attributes: {
-                title: Env.opacity ? Messages._getKey('cba_writtenBy', [name]) : undefined,
+                title: Env.opacity ? Messages._getKey('cba_writtenBy', [name]) : '',
                 'data-type': 'authormark',
                 'data-uid': uid
             }