diff --git a/modules/ext.RevisionSlider.less b/modules/ext.RevisionSlider.less
index fbc534a5..7a0b76f7 100644
--- a/modules/ext.RevisionSlider.less
+++ b/modules/ext.RevisionSlider.less
@@ -417,8 +417,8 @@ of the frameless one (to fit the size of the toggle button */
 }
 
 .mw-revslider-bubble {
-	height: 17px;
-	width: 17px;
+	height: 1.428571em;
+	width: 1.428571em;
 	background-color: #ccc;
 	border-radius: 100%;
 	display: inline-block;