diff --git a/composer.json b/composer.json
index 12046e9..11de187 100644
--- a/composer.json
+++ b/composer.json
@@ -12,7 +12,7 @@
         "php": ">=5.5"
     },
     "require-dev": {
-        "phpunit/phpunit": "7.*"
+        "phpunit/phpunit": "8.*"
     },
     "autoload": {
         "psr-4": {