diff --git a/inst/resources/gitbook/js/plugin-fontsettings.js b/inst/resources/gitbook/js/plugin-fontsettings.js
index 1121b6880..3ae3426bf 100644
--- a/inst/resources/gitbook/js/plugin-fontsettings.js
+++ b/inst/resources/gitbook/js/plugin-fontsettings.js
@@ -93,8 +93,7 @@ gitbook.require(["gitbook", "lodash", "jQuery"], function(gitbook, _, $) {
             $book[0].className = $book[0].className.replace(/\bcolor-theme-\S+/g, '');
             $book.addClass("color-theme-"+fontState.theme);
         }
-        $book[0].className = $book[0].className.replace(/\bline-height-\S+/g, '');
-        $book.addClass("line-height-" + fontState.spacing);
+        $book[0].querySelector('section').dataset.lineHeight = fontState.spacing / 10;
         
     };