diff --git a/composer.json b/composer.json
index b02b445..aadc5c3 100644
--- a/composer.json
+++ b/composer.json
@@ -23,7 +23,7 @@
     },
     "require-dev": {
         "mockery/mockery": "~1.3",
-        "phpunit/phpunit": "^5.0",
+        "phpunit/phpunit": "^6.2",
         "squizlabs/php_codesniffer": "^2.0",
         "friendsofphp/php-cs-fixer": "~1.0",
         "jakub-onderka/php-parallel-lint": "~0.9",