diff --git a/docs/BuildFromSource.md b/docs/BuildFromSource.md
index 95b08ab146..f16e82b559 100644
--- a/docs/BuildFromSource.md
+++ b/docs/BuildFromSource.md
@@ -38,7 +38,8 @@ Building ASP.NET Core on Windows requires:
     However, any Visual Studio 2019 instance that meets the requirements should be fine. See [global.json](/global.json)
     and [eng/scripts/vs.json](/eng/scripts/vs.json) for those requirements. By default, the script will install Visual Studio Enterprise Edition, however you can use a different edition by passing the `-Edition` flag.
 * Git. <https://git-scm.org>
-* NodeJS. LTS version of 10.14.2 or newer <https://nodejs.org>
+* NodeJS. LTS version of 10.14.2 or newer <https://nodejs.org>.
+* Install yarn globally (`npm install -g yarn`)
 * Java Development Kit 11 or newer. Either:
   * OpenJDK <https://jdk.java.net/>
   * Oracle's JDK <https://www.oracle.com/technetwork/java/javase/downloads/index.html>