diff --git a/.mergify.yml b/.mergify.yml
index fbc387b1e..071634989 100644
--- a/.mergify.yml
+++ b/.mergify.yml
@@ -10,6 +10,7 @@ pull_request_rules:
   - name: automatic merge
     conditions:
       - label!=DNM
+      - base=master
       - "#approved-reviews-by>=2"
       - "#changes-requested-reviews-by=0"
       - "status-success=continuous-integration/travis-ci/pr"