diff --git a/src/definitions/elements/header.less b/src/definitions/elements/header.less
index 637a3530e..682ec6298 100755
--- a/src/definitions/elements/header.less
+++ b/src/definitions/elements/header.less
@@ -703,7 +703,7 @@ a.ui.inverted.grey.header:hover {
 --------------------*/
 
 .ui.header:not(h1):not(h2):not(h3):not(h4):not(h5):not(h6) {
-  font-size: @medium;
+  font-size: @mediumFontSize;
 }
 
 .loadUIOverrides();