diff --git a/.travis.yml b/.travis.yml
index 6fcd103..265e73a 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -7,6 +7,8 @@ cache:
         - $HOME/.composer/cache
 
 php:
+    - 5.4
+    - 5.5
     - 5.6
     - 7.0