diff --git a/package.json b/package.json
index d61732dc..adceab0a 100644
--- a/package.json
+++ b/package.json
@@ -30,7 +30,6 @@
     "pub": "sh build/release.sh"
   },
   "dependencies": {
-    "document-ready": "^2.0.1",
     "marked": "^0.3.6",
     "prismjs": "^1.6.0",
     "tinydate": "^1.0.0",
diff --git a/src/core/index.js b/src/core/index.js
index 55e6fd3b..2e74419d 100644
--- a/src/core/index.js
+++ b/src/core/index.js
@@ -1,4 +1,3 @@
-import ready from 'document-ready'
 import { initMixin } from './init'
 import { routerMixin } from './router'
 import { renderMixin } from './render'
@@ -6,6 +5,19 @@ import { fetchMixin } from './fetch'
 import { eventMixin } from './event'
 import initGlobalAPI from './global-api'
 
+/**
+ * Fork https://github.com/bendrucker/document-ready/blob/master/index.js
+ */
+function ready (callback) {
+  const state = document.readyState
+
+  if (state === 'complete' || state === 'interactive') {
+    return setTimeout(callback, 0)
+  }
+
+  document.addEventListener('DOMContentLoaded', callback)
+}
+
 function Docsify () {
   this._init()
 }