diff --git a/packages/docsify-server-renderer/index.js b/packages/docsify-server-renderer/index.js
index 06aef617b..b07e40c07 100644
--- a/packages/docsify-server-renderer/index.js
+++ b/packages/docsify-server-renderer/index.js
@@ -74,7 +74,9 @@ export default class Renderer {
   }
 
   _renderHtml (match, content) {
-    return this.html = this.html.replace(new RegExp(`<!--${match}-->`, 'g'), content)
+    this.html = this.html.replace(new RegExp(`<!--${match}-->`, 'g'), content)
+
+    return this.html
   }
 
   _render (path, type) {
@@ -83,8 +85,8 @@ export default class Renderer {
 
     switch (type) {
       case 'sidebar':
-        html = this.compiler.sidebar(html, maxLevel)
-          + `<script>window.__SUB_SIDEBAR__ = ${JSON.stringify(
+        html = this.compiler.sidebar(html, maxLevel) +
+          `<script>window.__SUB_SIDEBAR__ = ${JSON.stringify(
             this.compiler.subSidebar(html, subMaxLevel)
           )}</script>`
         break
diff --git a/src/core/render/index.js b/src/core/render/index.js
index 652d4fc19..72244fd6d 100644
--- a/src/core/render/index.js
+++ b/src/core/render/index.js
@@ -79,7 +79,7 @@ export function renderMixin (proto) {
   }
 
   proto._renderSidebar = function (text) {
-    const { maxLevel, subMaxLevel, autoHeader, loadSidebar } = this.config
+    const { maxLevel, subMaxLevel, loadSidebar } = this.config
 
     this._renderTo('.sidebar-nav', this.compiler.sidebar(text, maxLevel))
     const activeEl = getAndActive(this.router, '.sidebar-nav', true, true)
@@ -171,7 +171,7 @@ export function initRender (vm) {
   const id = config.el || '#app'
   const navEl = dom.find('nav') || dom.create('nav')
 
-  let el = dom.find(id)
+  const el = dom.find(id)
   let html = ''
   let navAppendToTarget = dom.body