diff --git a/.travis.yml b/.travis.yml
index 570676fe..6f9921e6 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -8,5 +8,6 @@ install:
 script: $TRAVIS_BUILD_DIR/vendor/bin/phpunit
 language: php
 php:
+  - '5.6'
   - '7.0'
 after_failure: "cat /tmp/icehrm.test.log"