diff --git a/.travis.yml b/.travis.yml
index 24e4682..07414d5 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,7 +1,7 @@
 language: php
 php:
   - 5.6
-  - 7.1
+  - 7.0
   - hhvm
 
 before_script:
diff --git a/composer.json b/composer.json
index b3c9538..07a90e7 100644
--- a/composer.json
+++ b/composer.json
@@ -13,7 +13,7 @@
         "php": ">=5.3.0"
     },
     "require-dev": {
-        "phpunit/phpunit": "~5.5"
+        "phpunit/phpunit": "5.7.19"
     },
     "autoload": {
         "psr-4": {