diff --git a/.travis.yml b/.travis.yml
index 145b963..81c336b 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -7,10 +7,14 @@ matrix:
       elixir: 1.5
     - otp_release: 20.0
       elixir: 1.5
+    - otp_release: 21.0
+      elixir: 1.5
     - otp_release: 19.3
       elixir: 1.6
     - otp_release: 20.0
       elixir: 1.6
+    - otp_release: 21.0
+      elixir: 1.6
 sudo: false
 after_script:
   - MIX_ENV=docs mix deps.get