diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 2dd2a79..06e80e5 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -10,6 +10,9 @@ jobs:
       matrix:
         php: [ '7.2', '7.3', '7.4', '8.0']
         sf_version: [ '4.4.*', '5.3.*' ]
+        include:
+          - php: 8.0
+            sf_version: '6.0.*'
 
     steps:
       - name: Set up PHP
diff --git a/composer.json b/composer.json
index 4aafd85..59e3ff6 100644
--- a/composer.json
+++ b/composer.json
@@ -17,13 +17,13 @@
     "require": {
         "php": ">=7.2",
         "friendsofphp/proxy-manager-lts": "^1.0",
-        "symfony/config": "^4.4 || ^5.1",
-        "symfony/dependency-injection": "^4.4 || ^5.1",
-        "symfony/http-kernel": "^4.4 || ^5.1"
+        "symfony/config": "^4.4 || ^5.1 || ^6.0",
+        "symfony/dependency-injection": "^4.4 || ^5.1 || ^6.0",
+        "symfony/http-kernel": "^4.4 || ^5.1 || ^6.0"
     },
     "require-dev": {
         "nyholm/symfony-bundle-test": "^1.6",
-        "symfony/phpunit-bridge": "^4.4 || ^5.2"
+        "symfony/phpunit-bridge": "^5.3"
     },
     "autoload": {
         "psr-4": {
@@ -34,5 +34,7 @@
         "psr-4": {
             "Happyr\\ServiceMocking\\Tests\\": "tests/"
         }
-    }
+    },
+    "minimum-stability": "dev",
+    "prefer-stable": true
 }