diff --git a/.travis.yml b/.travis.yml
index db5dbc4..8b08d0b 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -3,6 +3,7 @@ sudo: required
 
 env:
   - ZSH=master
+  - ZSH=5.5
   - ZSH=5.4.2
   - ZSH=5.4.1
   - ZSH=5.4