diff --git a/extensions/chromium/options/options.html b/extensions/chromium/options/options.html
index 57ddae7b1..ef4bec4d0 100644
--- a/extensions/chromium/options/options.html
+++ b/extensions/chromium/options/options.html
@@ -43,6 +43,19 @@ body {
 </div>
 </template>
 
+<template id="viewerCssTheme-template">
+<div class="settings-row">
+  <label>
+    <span></span>
+    <select>
+      <option value="0">Use system theme</option>
+      <option value="1">Light theme</option>
+      <option value="2">Dark theme</option>
+    </select>
+  </label>
+</div>
+</template>
+
 <template id="viewOnLoad-template">
 <div class="settings-row">
   <label>
diff --git a/extensions/chromium/preferences_schema.json b/extensions/chromium/preferences_schema.json
index d6eb5d89b..49190d6ed 100644
--- a/extensions/chromium/preferences_schema.json
+++ b/extensions/chromium/preferences_schema.json
@@ -1,6 +1,17 @@
 {
   "type": "object",
   "properties": {
+    "viewerCssTheme": {
+      "title": "Theme",
+      "description": "The theme to use.\n0 = Use system theme.\n1 = Light theme.\n2 = Dark theme.",
+      "type": "integer",
+      "enum": [
+        0,
+        1,
+        2
+      ],
+      "default": 2
+    },
     "showPreviousViewOnLoad": {
       "description": "DEPRECATED. Set viewOnLoad to 1 to disable showing the last page/position on load.",
       "type": "boolean",
@@ -188,15 +199,6 @@
         2
       ],
       "default": -1
-    },
-    "viewerCssTheme": {
-      "type": "integer",
-      "enum": [
-        0,
-        1,
-        2
-      ],
-      "default": 0
     }
   }
 }
diff --git a/web/app_options.js b/web/app_options.js
index cd23a5691..9e152bd4d 100644
--- a/web/app_options.js
+++ b/web/app_options.js
@@ -177,7 +177,7 @@ const defaultOptions = {
   },
   viewerCssTheme: {
     /** @type {number} */
-    value: 0,
+    value: typeof PDFJSDev !== "undefined" && PDFJSDev.test("CHROME") ? 2 : 0,
     kind: OptionKind.VIEWER + OptionKind.PREFERENCE,
   },
   viewOnLoad: {