diff --git a/zephyr/static/styles/zephyr.css b/zephyr/static/styles/zephyr.css
index b2302c31c1..a4f33634c2 100644
--- a/zephyr/static/styles/zephyr.css
+++ b/zephyr/static/styles/zephyr.css
@@ -63,6 +63,7 @@ ul#sidebar {
     background-color: aliceblue;
     padding-left: 10px;
     padding-right: 20px;
+    overflow-x: hidden;
 }
 
 .message_row {