diff --git a/.travis.yml b/.travis.yml
index fd1cc86..f6b94b6 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -20,7 +20,7 @@ addons:
 env:
   global:
     - APP_NAME=registration
-    - CORE_BRANCH=master
+    - CORE_BRANCH=stable21
     - DB=sqlite
   matrix: