diff --git a/.npmrc b/.npmrc
index 77171bd..557bc0b 100644
--- a/.npmrc
+++ b/.npmrc
@@ -1,2 +1,3 @@
 package-lock=false
-optional=false
+optional=true
+force=true
diff --git a/README.md b/README.md
index 008d65e..f3da59a 100644
--- a/README.md
+++ b/README.md
@@ -26,7 +26,7 @@ Yet Another Minifier for Hexo. Minify and compress HTML, JS, CSS, SVG, XML and J
 ## Installation
 
 ```bash
-$ npm install hexo-yam --save
+$ npm install hexo-yam --save --include=optional --force
 ```
 
 ## Options