diff --git a/static/styles/zulip.css b/static/styles/zulip.css
index 25e436e951..6e36958ffd 100644
--- a/static/styles/zulip.css
+++ b/static/styles/zulip.css
@@ -1350,8 +1350,7 @@ td.pointer {
 
     .messagebox-content {
         box-shadow: inset 0 0 0 2px hsl(215, 47%, 50%),
-            -1px -1px 0 0 hsl(215, 47%, 50%), 1px 1px 0 0 hsl(215, 47%, 50%),
-            -1px 1px 0 0 hsl(215, 47%, 50%), 1px -1px 0 0 hsl(215, 47%, 50%);
+            0 0 0 1px hsl(215, 47%, 50%);
     }
 }