diff --git a/.travis.yml b/.travis.yml
index f78ea14..97dda12 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,7 +1,8 @@
 language: "php"
 php:
+    - "5.5"
     - "5.6"
-    - "7.0.4"
+    - "7.0"
     - "hhvm"
 
 before_script:
diff --git a/composer.json b/composer.json
index 394a2e6..986f380 100644
--- a/composer.json
+++ b/composer.json
@@ -29,12 +29,12 @@
         "bin-dir": "bin/"
     },
     "require": {
-        "php": ">= 5.6.0 || 7.0.0 - 7.0.4 || >= 7.0.6",
+        "php": ">= 5.5.9 || 7.0.0 - 7.0.4 || >= 7.0.6",
         "eugene-matvejev/compass": "^0.1",
         "leafo/lessphp": "^0.5"
     },
     "require-dev": {
         "composer/composer": "^1.1",
-        "phpunit/phpunit": "^5.3"
+        "phpunit/phpunit": "^4.8 || ^5.3"
     }
 }