diff --git a/src/core/index.js b/src/core/index.js
index 6e6164186..43db1eb15 100644
--- a/src/core/index.js
+++ b/src/core/index.js
@@ -4,5 +4,14 @@ import { Docsify } from './Docsify';
 /**
  * Run Docsify
  */
-// eslint-disable-next-line no-unused-vars
-documentReady(_ => new Docsify());
+const runDocsify = () => {
+  // eslint-disable-next-line no-unused-vars
+  documentReady(_ => new Docsify());
+};
+
+if (window.DOCSIFY_DEFER) {
+  window.runDocsify = runDocsify;
+} else {
+  window.runDocsify = () => {};
+  runDocsify();
+}