diff --git a/composer.json b/composer.json
index 2a8d893b..26c5bc12 100644
--- a/composer.json
+++ b/composer.json
@@ -14,5 +14,10 @@
 	"require": {
 		"php": ">=5.3.2",
 		"silverstripe/framework": ">=3.1.x-dev"
+	},
+	"extra": {
+		"branch-alias": {
+			"dev-master": "4.0.x-dev"
+		}
 	}
 }