diff --git a/templates/base.html b/templates/base.html
index a6721fc..37c4c5b 100644
--- a/templates/base.html
+++ b/templates/base.html
@@ -38,7 +38,7 @@
 
   <link rel="stylesheet" type="text/css"
     media="(prefers-color-scheme: dark)"
-    href="{{ SITEURL }}/{{ THEME_STATIC_DIR }}/pygments/{{ PYGMENTS_STYLE_DARK|default('github') }}.min.css">
+    href="{{ SITEURL }}/{{ THEME_STATIC_DIR }}/pygments/{{ PYGMENTS_STYLE_DARK|default('monokai') }}.min.css">
   <link rel="stylesheet" type="text/css"
     media="(prefers-color-scheme: light), (prefers-color-scheme: no-preference)"
     href="{{ SITEURL }}/{{ THEME_STATIC_DIR }}/pygments/{{ PYGMENTS_STYLE|default('github') }}.min.css">
diff --git a/templates/partial/flex.html b/templates/partial/flex.html
index 9514d99..80909e0 100644
--- a/templates/partial/flex.html
+++ b/templates/partial/flex.html
@@ -25,8 +25,8 @@
     // Find the pygments CSS files (there are two, one for each theme) and
     // change them both to the theme specified by the user.
     const pygmentsTheme = theme === 'light'
-      ? '{{ PYGMENTS_STYLE }}'
-      : '{{ PYGMENTS_STYLE_DARK or PYGMENTS_STYLE }}'
+      ? '{{ PYGMENTS_STYLE|default('github') }}'
+      : '{{ PYGMENTS_STYLE_DARK|default('monokai') }}'
     Array.from(document.head.getElementsByTagName('link')).forEach(linkEl => {
       if (linkEl.href.match(/\/theme\/pygments\/.*\.min\.css/)) {
         linkEl.href = `/theme/pygments/${pygmentsTheme}.min.css`;