diff --git a/README.md b/README.md
index 5e93efd8e2..c29ad314aa 100644
--- a/README.md
+++ b/README.md
@@ -16,6 +16,15 @@ jump right in to Electron development.
 
 ----
 
+## :rotating_light: :construction: **WARNING** :construction: :rotating_light:
+
+:building_construction:
+
+The `master` branch is a rewrite of Electron Forge that will eventually be the 6.x series. If you
+are looking for the 5.x series (the version currently published to NPM), please view the [5.x branch](https://github.com/electron-userland/electron-forge/tree/5.x).
+
+----
+
 [Website](https://electronforge.io) |
 [Goals](#project-goals) |
 [Usage](#usage) |