diff --git a/.travis.yml b/.travis.yml
index 7f2243e..17293ee 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,8 +1,10 @@
 language: php
 
 php:
+  - 5.3.3
   - 5.3
   - 5.4
+  - 5.5.9
   - 5.5
   - 5.6
   - 7.0