diff --git a/.travis.yml b/.travis.yml
index a6737fe..817bf4a 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -2,10 +2,33 @@ language: elixir
 notifications:
   recipients:
     - eduardo@gurgel.me
-elixir:
-  - 1.5.3
-otp_release:
-  - 19.0
-  - 20.0
+cache:
+  directories:
+    - _build
+    - deps
 sudo: false
 script: mix test
+matrix:
+  include:
+    - elixir: 1.5
+      otp_release: 19.3
+    - elixir: 1.5
+      otp_release: 20.3
+    - elixir: 1.6
+      otp_release: 19.3
+    - elixir: 1.6
+      otp_release: 20.3
+    - elixir: 1.6
+      otp_release: 21.0
+    - elixir: 1.7
+      otp_release: 19.3
+    - elixir: 1.7
+      otp_release: 20.3
+    - elixir: 1.7
+      otp_release: 21.0
+    - elixir: 1.8
+      otp_release: 20.3
+    - elixir: 1.8
+      otp_release: 21.0
+    - elixir: 1.8
+      otp_release: 22.0.1