diff --git a/src/librustdoc/config.rs b/src/librustdoc/config.rs
index a5fc07578169..baa0a9341267 100644
--- a/src/librustdoc/config.rs
+++ b/src/librustdoc/config.rs
@@ -1,4 +1,4 @@
-use std::collections::BTreeMap;
+use std::collections::{BTreeMap, HashMap};
 use std::convert::TryFrom;
 use std::ffi::OsStr;
 use std::fmt;
@@ -216,6 +216,9 @@ pub struct RenderOptions {
     pub extension_css: Option<PathBuf>,
     /// A map of crate names to the URL to use instead of querying the crate's `html_root_url`.
     pub extern_html_root_urls: BTreeMap<String, String>,
+    /// A map of the default settings (values are as for DOM storage API).  Keys should lack the
+    /// `rustdoc-` prefix.
+    pub default_settings: HashMap<String, String>,
     /// If present, suffix added to CSS/JavaScript files when referencing them in generated pages.
     pub resource_suffix: String,
     /// Whether to run the static CSS/JavaScript through a minifier when outputting them. `true` by
@@ -596,6 +599,7 @@ impl Options {
                 themes,
                 extension_css,
                 extern_html_root_urls,
+                default_settings: Default::default(),
                 resource_suffix,
                 enable_minification,
                 enable_index_page,
diff --git a/src/librustdoc/html/layout.rs b/src/librustdoc/html/layout.rs
index 7239b3c5ba2f..548911336625 100644
--- a/src/librustdoc/html/layout.rs
+++ b/src/librustdoc/html/layout.rs
@@ -1,3 +1,4 @@
+use std::collections::HashMap;
 use std::path::PathBuf;
 
 use crate::externalfiles::ExternalHtml;
@@ -10,6 +11,7 @@ pub struct Layout {
     pub logo: String,
     pub favicon: String,
     pub external_html: ExternalHtml,
+    pub default_settings: HashMap<String, String>,
     pub krate: String,
     /// The given user css file which allow to customize the generated
     /// documentation theme.
@@ -53,6 +55,7 @@ pub fn render<T: Print, S: Print>(
     <link rel=\"stylesheet\" type=\"text/css\" href=\"{static_root_path}rustdoc{suffix}.css\" \
           id=\"mainThemeStyle\">\
     {style_files}\
+    <script id=\"default-settings\"{default_settings}></script>\
     <script src=\"{static_root_path}storage{suffix}.js\"></script>\
     <noscript><link rel=\"stylesheet\" href=\"{static_root_path}noscript{suffix}.css\"></noscript>\
     {css_extension}\
@@ -172,6 +175,11 @@ pub fn render<T: Print, S: Print>(
         after_content = layout.external_html.after_content,
         sidebar = Buffer::html().to_display(sidebar),
         krate = layout.krate,
+        default_settings = layout
+            .default_settings
+            .iter()
+            .map(|(k, v)| format!(r#" data-{}="{}""#, k.replace('-',"_"), Escape(v),))
+            .collect::<String>(),
         style_files = style_files
             .iter()
             .filter_map(|t| {
diff --git a/src/librustdoc/html/markdown.rs b/src/librustdoc/html/markdown.rs
index 2fd06d7e5730..ca8b811681cc 100644
--- a/src/librustdoc/html/markdown.rs
+++ b/src/librustdoc/html/markdown.rs
@@ -1228,6 +1228,7 @@ fn init_id_map() -> FxHashMap<String, usize> {
     map.insert("render-detail".to_owned(), 1);
     map.insert("toggle-all-docs".to_owned(), 1);
     map.insert("all-types".to_owned(), 1);
+    map.insert("default-settings".to_owned(), 1);
     // This is the list of IDs used by rustdoc sections.
     map.insert("fields".to_owned(), 1);
     map.insert("variants".to_owned(), 1);
diff --git a/src/librustdoc/html/render/mod.rs b/src/librustdoc/html/render/mod.rs
index 1726093c6fac..0621eafd9134 100644
--- a/src/librustdoc/html/render/mod.rs
+++ b/src/librustdoc/html/render/mod.rs
@@ -392,6 +392,7 @@ impl FormatRenderer for Context {
             playground_url,
             sort_modules_alphabetically,
             themes: style_files,
+            default_settings,
             extension_css,
             resource_suffix,
             static_root_path,
@@ -415,6 +416,7 @@ impl FormatRenderer for Context {
             logo: String::new(),
             favicon: String::new(),
             external_html,
+            default_settings,
             krate: krate.name.clone(),
             css_file_extension: extension_css,
             generate_search_filter,
diff --git a/src/librustdoc/html/static/storage.js b/src/librustdoc/html/static/storage.js
index 179d71320575..d081781f14be 100644
--- a/src/librustdoc/html/static/storage.js
+++ b/src/librustdoc/html/static/storage.js
@@ -5,8 +5,30 @@ var darkThemes = ["dark", "ayu"];
 var currentTheme = document.getElementById("themeStyle");
 var mainTheme = document.getElementById("mainThemeStyle");
 
+var settingsDataset = (function () {
+    var settingsElement = document.getElementById("default-settings");
+    if (settingsElement === null) {
+        return null;
+    }
+    var dataset = settingsElement.dataset;
+    if (dataset === undefined) {
+        return null;
+    }
+    return dataset;
+})();
+
 function getSettingValue(settingName) {
-    return getCurrentValue('rustdoc-' + settingName);
+    var current = getCurrentValue('rustdoc-' + settingName);
+    if (current !== null) {
+        return current;
+    }
+    if (settingsDataset !== null) {
+        var def = settingsDataset[settingName.replace(/-/g,'_')];
+        if (def !== undefined) {
+            return def;
+        }
+    }
+    return null;
 }
 
 var localStoredTheme = getSettingValue("theme");