diff --git a/composer.json b/composer.json
index 86fa85b4d4a..e27a7ee27c8 100644
--- a/composer.json
+++ b/composer.json
@@ -11,7 +11,7 @@
     ],
     "require": {
         "php": ">=5.4",
-        "nikic/PHP-Parser": "2.1.0"
+        "nikic/PHP-Parser": ">=2.1.0"
     },
     "bin": ["bin/psalm"],
     "autoload": {
@@ -25,7 +25,7 @@
         }
     },
     "require-dev": {
-        "phpunit/phpunit": "^5.6"
+        "phpunit/phpunit": ">=4.1"
     },
     "scripts": {
         "psalm": "./bin/psalm --self-check",