diff --git a/.travis.yml b/.travis.yml
index a0d7056..2033754 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -5,8 +5,8 @@ notifications:
 elixir:
   - 1.5.3
 otp_release:
+  - 18.0
   - 19.0
   - 20.0
-  - 21.0.1
 sudo: false
 script: mix test