diff --git a/.circleci/config.yml b/.circleci/config.yml
index 6095615..078f303 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -1,4 +1,4 @@
-version: 2
+version: 2.1
 jobs:
   build_mac:
     docker: