diff --git a/inst/rmd/h/default.html b/inst/rmd/h/default.html
index e61b004c87..226d863a39 100644
--- a/inst/rmd/h/default.html
+++ b/inst/rmd/h/default.html
@@ -32,7 +32,17 @@
 <style type="text/css">code{white-space: pre;}</style>
 $if(theme)$
 <style type="text/css">
-  pre:not([class]) {
+  pre:not([class]),
+  pre[class="sourceCode numberSource numberLines"],
+  pre[class="sourceCode numberSource numberLines lineAnchors"],
+  pre[class="sourceCode numberSource numberLines line-anchors"],
+  pre[class="sourceCode numberSource number-lines"],
+  pre[class="sourceCode numberSource number-lines lineAnchors"],
+  pre[class="sourceCode numberSource number-lines line-anchors"],
+  pre[class="sourceCode numberSource lineAnchors numberLines"],
+  pre[class="sourceCode numberSource lineAnchors number-lines"],
+  pre[class="sourceCode numberSource line-anchors numberLines"],
+  pre[class="sourceCode numberSource line-anchors number-lines"] {
     background-color: white;
   }
 </style>
@@ -88,7 +98,17 @@
 </script>
 $if(theme)$
 <style type="text/css">
-  pre:not([class]) {
+  pre:not([class]),
+  pre[class="sourceCode numberSource numberLines"],
+  pre[class="sourceCode numberSource numberLines lineAnchors"],
+  pre[class="sourceCode numberSource numberLines line-anchors"],
+  pre[class="sourceCode numberSource number-lines"],
+  pre[class="sourceCode numberSource number-lines lineAnchors"],
+  pre[class="sourceCode numberSource number-lines line-anchors"],
+  pre[class="sourceCode numberSource lineAnchors numberLines"],
+  pre[class="sourceCode numberSource lineAnchors number-lines"],
+  pre[class="sourceCode numberSource line-anchors numberLines"],
+  pre[class="sourceCode numberSource line-anchors number-lines"] {
     background-color: white;
   }
 </style>