diff --git a/composer.json b/composer.json
index 6e3b395..dc79fd8 100644
--- a/composer.json
+++ b/composer.json
@@ -19,11 +19,8 @@
             "Gabeta\\GsmDetector\\Test\\": "tests"
         }
     },
-    "require": {
-        "php": "^5.4|^5.5|^5.6|^7.0|^7.1|^7.2|^7.3|^7.4"
-    },
     "require-dev": {
-        "phpunit/phpunit": "^4|^5|^6|^7|^8|^9"
+        "phpunit/phpunit": "^8"
     },
     "scripts": {
         "test": "vendor/bin/phpunit tests"