diff --git a/src/docbkx/resources/css/html.css b/src/docbkx/resources/css/html.css
index 10936f337..994a3acfb 100644
--- a/src/docbkx/resources/css/html.css
+++ b/src/docbkx/resources/css/html.css
@@ -1,3 +1,5 @@
+@IMPORT url("highlight.css");
+
 body {
     text-align: justify;
     margin-right: 2em;