diff --git a/.travis.yml b/.travis.yml
index ea3a4c3..db2be2a 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,5 +1,7 @@
 language: ruby
 rvm:
+  - 2.3
+  - 2.4
   - 2.5
   - 2.6
 script: