diff --git a/pelican/themes/notmyidea/static/css/main.css b/pelican/themes/notmyidea/static/css/main.css
index d351f4d8..838358ce 100644
--- a/pelican/themes/notmyidea/static/css/main.css
+++ b/pelican/themes/notmyidea/static/css/main.css
@@ -118,6 +118,10 @@ pre {
   overflow-x: auto;
 }
 
+.highlight {
+  overflow: auto;
+}
+
 /* Quotes */
 blockquote {
   background: #f9f9f9;