diff --git a/.travis.yml b/.travis.yml
index 2ea586e..ab65f2a 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -4,6 +4,7 @@ php:
   - 7.2
   - 7.3
   - 7.4
+  - 8.0
 
 before_script:
   - composer install
diff --git a/composer.json b/composer.json
index 959303e..6866213 100644
--- a/composer.json
+++ b/composer.json
@@ -11,15 +11,15 @@
   ],
   "license": "MIT",
   "require": {
-    "php": ">=7.2",
+    "php": "^7.2 || ^8.0",
     "ext-dom": "*",
     "ext-json": "*",
     "ext-libxml": "*",
     "sabre/uri": "^2.1"
   },
   "require-dev": {
-    "phpunit/phpunit": "8.*",
-    "php-coveralls/php-coveralls": "2.*"
+    "phpunit/phpunit": "^8.0 || ^9.0",
+    "php-coveralls/php-coveralls": "^2.0"
   },
   "autoload": {
     "psr-4": {