diff --git a/packages/docusaurus/lib/client/clientEntry.js b/packages/docusaurus/lib/client/clientEntry.js
index c26e6a6036..967aec9e65 100644
--- a/packages/docusaurus/lib/client/clientEntry.js
+++ b/packages/docusaurus/lib/client/clientEntry.js
@@ -16,7 +16,7 @@ import routes from '@generated/routes'; // eslint-disable-line
 
 // Client-side render (e.g: running in browser) to become single-page application (SPA).
 if (typeof window !== 'undefined' && typeof document !== 'undefined') {
-  window.__docusaurus = docusaurus;
+  window.docusaurus = docusaurus;
   // For production, attempt to hydrate existing markup for performant first-load experience.
   // For development, there is no existing markup so we had to render it.
   // Note that we also preload async component to avoid first-load loading screen.
diff --git a/packages/docusaurus/lib/client/docusaurus.js b/packages/docusaurus/lib/client/docusaurus.js
index 3a0e752cc8..7926314f8c 100644
--- a/packages/docusaurus/lib/client/docusaurus.js
+++ b/packages/docusaurus/lib/client/docusaurus.js
@@ -9,32 +9,10 @@ import routesChunkNames from '@generated/routesChunkNames';
 import routes from '@generated/routes'; // eslint-disable-line
 import prefetchHelper from './prefetch';
 import preloadHelper from './preload';
+import flat from './flat';
 
 const fetched = {};
 
-function flatten(target) {
-  const delimiter = '.';
-  const output = {};
-
-  function step(object, prev) {
-    Object.keys(object).forEach(key => {
-      const value = object[key];
-      const isArray = Array.isArray(value);
-      const type = typeof value;
-      const isObject = type === 'object' && !!value;
-      const newKey = prev ? prev + delimiter + key : key;
-
-      if (!isArray && isObject && Object.keys(value).length) {
-        step(value, newKey);
-        return;
-      }
-      output[newKey] = value;
-    });
-  }
-  step(target);
-  return output;
-}
-
 const canPrefetchOrLoad = routePath => {
   // if user is on slow or constrained connection
   if (`connection` in navigator) {
@@ -58,7 +36,7 @@ const docusaurus = {
     const matches = matchRoutes(routes, routePath);
     const chunkNamesNeeded = matches.reduce((arr, match) => {
       const chunkNames = Object.values(
-        flatten(routesChunkNames[match.route.path]),
+        flat(routesChunkNames[match.route.path]),
       );
       return arr.concat(chunkNames);
     }, []);
diff --git a/packages/docusaurus/lib/client/exports/Link.js b/packages/docusaurus/lib/client/exports/Link.js
index 257b77d76b..b7c7b03726 100644
--- a/packages/docusaurus/lib/client/exports/Link.js
+++ b/packages/docusaurus/lib/client/exports/Link.js
@@ -42,7 +42,7 @@ function Link(props) {
     if (IOSupported && ref && isInternal) {
       // If IO supported and element reference found, setup Observer functionality
       handleIntersection(ref, () => {
-        window.__docusaurus.prefetch(targetLink);
+        window.docusaurus.prefetch(targetLink);
       });
     }
   };
@@ -50,7 +50,7 @@ function Link(props) {
   useEffect(() => {
     // If IO is not supported. We prefetch by default (only once)
     if (!IOSupported && isInternal) {
-      window.__docusaurus.prefetch(targetLink);
+      window.docusaurus.prefetch(targetLink);
     }
     // when unmount, stops intersection observer from watching
     return () => {
@@ -66,7 +66,7 @@ function Link(props) {
   ) : (
     <Perimeter
       padding={preloadProximity}
-      onBreach={() => window.__docusaurus.preload(targetLink)}
+      onBreach={() => window.docusaurus.preload(targetLink)}
       once>
       <NavLink {...props} innerRef={handleRef} to={targetLink} />
     </Perimeter>
diff --git a/packages/docusaurus/lib/client/flat.js b/packages/docusaurus/lib/client/flat.js
new file mode 100644
index 0000000000..4d9ee5703a
--- /dev/null
+++ b/packages/docusaurus/lib/client/flat.js
@@ -0,0 +1,30 @@
+/**
+ * Copyright (c) 2017-present, Facebook, Inc.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+function flat(target) {
+  const delimiter = '.';
+  const output = {};
+
+  function step(object, prev) {
+    Object.keys(object).forEach(key => {
+      const value = object[key];
+      const type = typeof value;
+      const isObject = type === 'object' && !!value;
+      const newKey = prev ? prev + delimiter + key : key;
+
+      if (isObject && Object.keys(value).length) {
+        step(value, newKey);
+        return;
+      }
+      output[newKey] = value;
+    });
+  }
+  step(target);
+  return output;
+}
+
+export default flat;
diff --git a/packages/docusaurus/test/client/flat.test.js b/packages/docusaurus/test/client/flat.test.js
new file mode 100644
index 0000000000..99c0fd0672
--- /dev/null
+++ b/packages/docusaurus/test/client/flat.test.js
@@ -0,0 +1,94 @@
+/**
+ * Copyright (c) 2017-present, Facebook, Inc.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+import flat from '@lib/client/flat';
+
+describe('flat', () => {
+  test('nested', () => {
+    expect(
+      flat({
+        foo: {
+          bar: {
+            baz: 'lorem ipsum',
+          },
+        },
+      }),
+    ).toEqual({
+      'foo.bar.baz': 'lorem ipsum',
+    });
+
+    expect(
+      flat({
+        foo: {
+          bar: 'baz',
+        },
+      }),
+    ).toEqual({
+      'foo.bar': 'baz',
+    });
+  });
+
+  test('primitives', () => {
+    const primitives = {
+      String: 'good morning',
+      Number: 1234.99,
+      Boolean: true,
+      Date: new Date(),
+      null: null,
+      undefined,
+    };
+    Object.keys(primitives).forEach(key => {
+      const value = primitives[key];
+      expect(
+        flat({
+          foo: {
+            bar: value,
+          },
+        }),
+      ).toEqual({
+        'foo.bar': value,
+      });
+    });
+  });
+
+  test('multiple keys', () => {
+    expect(
+      flat({
+        foo: {
+          bar: 'baz',
+          endi: 'lie',
+        },
+      }),
+    ).toEqual({
+      'foo.bar': 'baz',
+      'foo.endi': 'lie',
+    });
+  });
+
+  test('empty object', () => {
+    expect(
+      flat({
+        foo: {
+          bar: {},
+        },
+      }),
+    ).toEqual({
+      'foo.bar': {},
+    });
+  });
+
+  test('array', () => {
+    expect(
+      flat({
+        hello: [{world: {again: 'foo'}}, {lorem: 'ipsum'}],
+      }),
+    ).toEqual({
+      'hello.0.world.again': 'foo',
+      'hello.1.lorem': 'ipsum',
+    });
+  });
+});
diff --git a/website/pages/index.js b/website/pages/index.js
index ef4e0d03fd..cfc0275a65 100644
--- a/website/pages/index.js
+++ b/website/pages/index.js
@@ -68,8 +68,8 @@ function Home() {
 
   useEffect(() => {
     // Prefetch feedback pages & getting started pages
-    __docusaurus.prefetch(feedbackUrl);
-    __docusaurus.prefetch(gettingStartedUrl);
+    window.docusaurus.prefetch(feedbackUrl);
+    window.docusaurus.prefetch(gettingStartedUrl);
   }, []);
 
   return (