diff --git a/docs/setup.en.md b/docs/setup.en.md
index 88e20f6bc..ec062e947 100644
--- a/docs/setup.en.md
+++ b/docs/setup.en.md
@@ -53,7 +53,12 @@ Or you can generate config file via `npm run config` command.
 
 *5.* Build Misskey
 ----------------------------------------------------------------
-1. `npm run build`
+We need to use `node-gyp` to build the `crypto` module.
+
+1. `npm install -g node-gyp`
+2.  `node-gyp configure`
+3. `node-gyp build`
+4. `npm run build`
 
 *6.* That is it.
 ----------------------------------------------------------------