diff --git a/.travis.yml b/.travis.yml
index 6fb8618..a4cdff0 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,4 +1,5 @@
 language: ruby
 rvm:
-  - 2.2.3
-before_install: gem install bundler -v 1.10.6
+  - 2.2.6
+  - 2.3.2
+  - 2.4.0-preview3