diff --git a/.github/workflows/acceptance.yml b/.github/workflows/acceptance.yml
index c3629af..d18d7b8 100644
--- a/.github/workflows/acceptance.yml
+++ b/.github/workflows/acceptance.yml
@@ -12,7 +12,7 @@ jobs:
     name: Unit test
     steps:
     - name: Checkout
-      uses: actions/checkout@v3
+      uses: actions/checkout@v4
     - name: Set up PHP
       uses: shivammathur/setup-php@v2
       with:
@@ -39,7 +39,7 @@ jobs:
     name: Code standard
     steps:
     - name: Checkout
-      uses: actions/checkout@v3
+      uses: actions/checkout@v4
     - name: Set up PHP
       uses: shivammathur/setup-php@v2
       with:
@@ -66,7 +66,7 @@ jobs:
     name: Code coverage
     steps:
     - name: Checkout
-      uses: actions/checkout@v3
+      uses: actions/checkout@v4
     - name: Set up PHP
       uses: shivammathur/setup-php@v2
       with:
diff --git a/composer.json b/composer.json
index c66ed4b..918e310 100644
--- a/composer.json
+++ b/composer.json
@@ -26,7 +26,7 @@
         }
     },
     "require": {
-        "php": "^8.1",
+        "php": "^8.0",
         "phrity/net-uri": "^1.2",
         "phrity/net-stream": "^1.3",
         "phrity/util-errorhandler": "^1.0",