diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 6f6c894..67bb073 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -1,4 +1,4 @@
-image: "ruby:2.3"
+image: "ruby:2.1"
 
 before_script:
   - apt-get update; apt-get install -y check libev-dev net-tools