diff --git a/packages/docusaurus-plugin-content-docs/src/__tests__/sidebars.test.ts b/packages/docusaurus-plugin-content-docs/src/__tests__/sidebars.test.ts
index 0a153e45f8..e2f9b66a11 100644
--- a/packages/docusaurus-plugin-content-docs/src/__tests__/sidebars.test.ts
+++ b/packages/docusaurus-plugin-content-docs/src/__tests__/sidebars.test.ts
@@ -52,4 +52,10 @@ describe('loadSidebars', () => {
     const result = loadSidebars(null);
     expect(result).toEqual({});
   });
+
+  test('fake sidebars path', () => {
+    expect(() => {
+      loadSidebars('/fake/path');
+    }).toThrowError();
+  });
 });
diff --git a/packages/docusaurus-plugin-content-docs/src/sidebars.ts b/packages/docusaurus-plugin-content-docs/src/sidebars.ts
index dd0d108a41..be972049a5 100644
--- a/packages/docusaurus-plugin-content-docs/src/sidebars.ts
+++ b/packages/docusaurus-plugin-content-docs/src/sidebars.ts
@@ -5,7 +5,6 @@
  * LICENSE file in the root directory of this source tree.
  */
 
-import fs from 'fs';
 import importFresh from 'import-fresh';
 import {
   SidebarItemCategory,
@@ -105,7 +104,7 @@ function normalizeSidebar(sidebars: SidebarRaw): Sidebar {
 export default function loadSidebars(sidebarPath: string): Sidebar {
   // We don't want sidebars to be cached because of hotreloading.
   let allSidebars: SidebarRaw = {};
-  if (sidebarPath && fs.existsSync(sidebarPath)) {
+  if (sidebarPath) {
     allSidebars = importFresh(sidebarPath) as SidebarRaw;
   }
   return normalizeSidebar(allSidebars);
diff --git a/packages/docusaurus/src/client/serverEntry.js b/packages/docusaurus/src/client/serverEntry.js
index ae5304a7ca..d9ccb94e42 100644
--- a/packages/docusaurus/src/client/serverEntry.js
+++ b/packages/docusaurus/src/client/serverEntry.js
@@ -14,75 +14,74 @@ import {getBundles} from 'react-loadable-ssr-addon';
 import Loadable from 'react-loadable';
 
 import path from 'path';
-import fs from 'fs';
+import fs from 'fs-extra';
 import routes from '@generated/routes';
 import preload from './preload';
 import App from './App';
 import ssrTemplate from './templates/ssr.html.template';
 
 // Renderer for static-site-generator-webpack-plugin (async rendering via promises)
-export default function render(locals) {
+export default async function render(locals) {
   const {routesLocation} = locals;
   const location = routesLocation[locals.path];
-  return preload(routes, location).then(() => {
-    const modules = new Set();
-    const context = {};
-    const appHtml = ReactDOMServer.renderToString(
-      <Loadable.Capture report={moduleName => modules.add(moduleName)}>
-        <StaticRouter location={location} context={context}>
-          <App />
-        </StaticRouter>
-      </Loadable.Capture>,
-    );
+  await preload(routes, location);
+  const modules = new Set();
+  const context = {};
+  const appHtml = ReactDOMServer.renderToString(
+    <Loadable.Capture report={moduleName => modules.add(moduleName)}>
+      <StaticRouter location={location} context={context}>
+        <App />
+      </StaticRouter>
+    </Loadable.Capture>,
+  );
 
-    const helmet = Helmet.renderStatic();
-    const htmlAttributes = helmet.htmlAttributes.toString();
-    const bodyAttributes = helmet.bodyAttributes.toString();
-    const metaStrings = [
-      helmet.title.toString(),
-      helmet.meta.toString(),
-      helmet.link.toString(),
-    ];
-    const metaAttributes = metaStrings.filter(Boolean);
+  const helmet = Helmet.renderStatic();
+  const htmlAttributes = helmet.htmlAttributes.toString();
+  const bodyAttributes = helmet.bodyAttributes.toString();
+  const metaStrings = [
+    helmet.title.toString(),
+    helmet.meta.toString(),
+    helmet.link.toString(),
+  ];
+  const metaAttributes = metaStrings.filter(Boolean);
 
-    const {outDir} = locals;
-    const manifestPath = path.join(outDir, 'client-manifest.json');
-    const manifest = JSON.parse(fs.readFileSync(manifestPath, 'utf8'));
+  const {outDir} = locals;
+  const manifestPath = path.join(outDir, 'client-manifest.json');
+  const manifest = JSON.parse(await fs.readFile(manifestPath, 'utf8'));
 
-    // chunkName -> chunkAssets mapping.
-    const chunkManifestPath = path.join(outDir, 'chunk-map.json');
-    const chunkManifest = JSON.parse(
-      fs.readFileSync(chunkManifestPath, 'utf-8'),
-    );
-    const chunkManifestScript =
-      `<script type="text/javascript">` +
-      `/*<![CDATA[*/window.__chunkMapping=${JSON.stringify(
-        chunkManifest,
-      )};/*]]>*/` +
-      `</script>`;
+  // chunkName -> chunkAssets mapping.
+  const chunkManifestPath = path.join(outDir, 'chunk-map.json');
+  const chunkManifest = JSON.parse(
+    await fs.readFile(chunkManifestPath, 'utf8'),
+  );
+  const chunkManifestScript =
+    `<script type="text/javascript">` +
+    `/*<![CDATA[*/window.__chunkMapping=${JSON.stringify(
+      chunkManifest,
+    )};/*]]>*/` +
+    `</script>`;
 
-    // Get all required assets for this particular page based on client manifest information
-    const modulesToBeLoaded = [...manifest.entrypoints, ...Array.from(modules)];
-    const bundles = getBundles(manifest, modulesToBeLoaded);
-    const stylesheets = (bundles.css || []).map(b => b.file);
-    const scripts = (bundles.js || []).map(b => b.file);
-    const {baseUrl} = locals;
+  // Get all required assets for this particular page based on client manifest information
+  const modulesToBeLoaded = [...manifest.entrypoints, ...Array.from(modules)];
+  const bundles = getBundles(manifest, modulesToBeLoaded);
+  const stylesheets = (bundles.css || []).map(b => b.file);
+  const scripts = (bundles.js || []).map(b => b.file);
+  const {baseUrl} = locals;
 
-    return ejs.render(
-      ssrTemplate.trim(),
-      {
-        appHtml,
-        baseUrl,
-        chunkManifestScript,
-        htmlAttributes: htmlAttributes || '',
-        bodyAttributes: bodyAttributes || '',
-        metaAttributes,
-        scripts,
-        stylesheets,
-      },
-      {
-        rmWhitespace: true,
-      },
-    );
-  });
+  return ejs.render(
+    ssrTemplate.trim(),
+    {
+      appHtml,
+      baseUrl,
+      chunkManifestScript,
+      htmlAttributes: htmlAttributes || '',
+      bodyAttributes: bodyAttributes || '',
+      metaAttributes,
+      scripts,
+      stylesheets,
+    },
+    {
+      rmWhitespace: true,
+    },
+  );
 }
diff --git a/packages/docusaurus/src/commands/build.ts b/packages/docusaurus/src/commands/build.ts
index 5c10bea033..10beb08754 100644
--- a/packages/docusaurus/src/commands/build.ts
+++ b/packages/docusaurus/src/commands/build.ts
@@ -110,7 +110,9 @@ export async function build(
   // Remove server.bundle.js because it is useless
   if (serverConfig.output && serverConfig.output.filename) {
     const serverBundle = path.join(outDir, serverConfig.output.filename);
-    fs.existsSync(serverBundle) && fs.unlinkSync(serverBundle);
+    fs.pathExists(serverBundle).then(exist => {
+      exist && fs.unlink(serverBundle);
+    });
   }
 
   /* Plugin lifecycle - postBuild */
diff --git a/packages/docusaurus/src/webpack/plugins/ChunkManifestPlugin.js b/packages/docusaurus/src/webpack/plugins/ChunkManifestPlugin.js
index 607ee9c80e..82ca50ad78 100644
--- a/packages/docusaurus/src/webpack/plugins/ChunkManifestPlugin.js
+++ b/packages/docusaurus/src/webpack/plugins/ChunkManifestPlugin.js
@@ -26,7 +26,7 @@ class ChunkManifestPlugin {
     const {path: outputPath, publicPath} = compiler.options.output;
 
     // Build the chunk mapping
-    compiler.hooks.afterCompile.tap(pluginName, compilation => {
+    compiler.hooks.afterCompile.tapAsync(pluginName, (compilation, done) => {
       const assets = {};
       const assetsMap = {};
       // eslint-disable-next-line
@@ -50,8 +50,11 @@ class ChunkManifestPlugin {
       chunkManifest = assetsMap;
       if (!this.options.inlineManifest) {
         const finalPath = path.resolve(outputPath, this.options.filename);
-        fs.ensureDirSync(path.dirname(finalPath));
-        fs.writeFileSync(finalPath, JSON.stringify(chunkManifest, null, 2));
+        fs.ensureDir(path.dirname(finalPath), () => {
+          fs.writeFile(finalPath, JSON.stringify(chunkManifest, null, 2), done);
+        });
+      } else {
+        done();
       }
     });
 
diff --git a/packages/docusaurus/src/webpack/plugins/WaitPlugin.js b/packages/docusaurus/src/webpack/plugins/WaitPlugin.js
index e0a5100c86..3412376c87 100644
--- a/packages/docusaurus/src/webpack/plugins/WaitPlugin.js
+++ b/packages/docusaurus/src/webpack/plugins/WaitPlugin.js
@@ -18,19 +18,19 @@ class WaitPlugin {
     // Before finishing the compilation step
     compiler.hooks.make.tapAsync('WaitPlugin', (compilation, callback) => {
       // To prevent 'waitFile' error on waiting non-existing directory
-      fs.ensureDirSync(path.dirname(this.filepath));
-
-      // Wait until file exist
-      waitFile({
-        resources: [this.filepath],
-        interval: 300,
-      })
-        .then(() => {
-          callback();
+      fs.ensureDir(path.dirname(this.filepath), () => {
+        // Wait until file exist
+        waitFile({
+          resources: [this.filepath],
+          interval: 300,
         })
-        .catch(error => {
-          console.warn(`WaitPlugin error: ${error}`);
-        });
+          .then(() => {
+            callback();
+          })
+          .catch(error => {
+            console.warn(`WaitPlugin error: ${error}`);
+          });
+      });
     });
   }
 }