diff --git a/.travis.yml b/.travis.yml
index 37a1cdd..4eb42cf 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -16,7 +16,7 @@ rvm:
   - truffleruby-1.0.0-rc12
 
   # Older versions
-  - 2.5.4
+  - 2.5.5
   - 2.4.5
   - 2.3.8
   - 2.2.10