diff --git a/composer.json b/composer.json
index 6741981..a63be6d 100644
--- a/composer.json
+++ b/composer.json
@@ -41,7 +41,7 @@
     },
     "require-dev": {
         "mikey179/vfsStream": "^1.6",
-        "phpunit/phpunit": "^5.7",
+        "phpunit/phpunit": "^7.0",
         "squizlabs/php_codesniffer": "^3.2"
     }
 }