diff --git a/.travis.yml b/.travis.yml
index 59730be..0156f51 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,4 +1,8 @@
 language: ruby
+os:
+  - linux
+  - osx
+  - windows
 rvm:
   - 2.4
   - 2.5