diff --git a/.travis.yml b/.travis.yml
index 1ccb0457..3773b9ec 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -14,7 +14,6 @@ cache:
 env:
   global:
     - COMPOSER_ROOT_VERSION=4.x-dev
-    - CORE_RELEASE=master
 
 matrix:
   fast_finish: true