--- a/browser/themes/shared/privatebrowsing/aboutPrivateBrowsing.css
+++ b/browser/themes/shared/privatebrowsing/aboutPrivateBrowsing.css
@@ -63,17 +63,18 @@ p {
 
 .list-row {
   overflow: auto;
 }
 
 .list-row > ul > li {
   float: left;
   width: 220px;
-  margin-left: 1em;
+  line-height: 1.5em;
+  -moz-margin-start: 1em;
   margin-bottom: 0;
 }
 
 .title {
   background-image: url("chrome://browser/skin/privatebrowsing/private-browsing.svg");
   background-size: 64px;
   background-position: left, center;
   font-weight: lighter;