diff --git a/README.md b/README.md
index b2ce691..acd821d 100644
--- a/README.md
+++ b/README.md
@@ -57,6 +57,7 @@ Thanks for using! :smile:
 - Node.js 6.x or up (test up to 7.5.0)
 - Database (PostgreSQL, MySQL, MariaDB, SQLite, MSSQL) use charset `utf8`
 - npm (and its dependencies, especially [uWebSockets](https://github.com/uWebSockets/uWebSockets#nodejs-developers), [node-gyp](https://github.com/nodejs/node-gyp#installation))
+- For **building** HackMD we recommend to use a machine with at least **2GB** RAM
 
 ### Instructions