diff --git a/media/css/firefox/all.less b/media/css/firefox/all.less
index 95888ce11f..32cf5a42a4 100644
--- a/media/css/firefox/all.less
+++ b/media/css/firefox/all.less
@@ -193,6 +193,7 @@
         width: 40px;
         height: 40px;
         text-indent: 200%;
+        white-space: nowrap;
     }
 }