diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 1bb8701..b2645b4 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -7,10 +7,11 @@ on:
 jobs:
   PHPUnit:
     name: PHPUnit (PHP ${{ matrix.php }})
-    runs-on: ubuntu-22.04
+    runs-on: ubuntu-24.04
     strategy:
       matrix:
         php:
+          - 8.4
           - 8.3
           - 8.2
           - 8.1
@@ -35,7 +36,7 @@ jobs:
 
   PHPUnit-macOS:
     name: PHPUnit (macOS)
-    runs-on: macos-12
+    runs-on: macos-14
     continue-on-error: true
     steps:
       - uses: actions/checkout@v4
@@ -50,10 +51,11 @@ jobs:
 
   PHPStan:
     name: PHPStan (PHP ${{ matrix.php }})
-    runs-on: ubuntu-22.04
+    runs-on: ubuntu-24.04
     strategy:
       matrix:
         php:
+          - 8.4
           - 8.3
           - 8.2
           - 8.1
diff --git a/composer.json b/composer.json
index beb0a56..00c2378 100644
--- a/composer.json
+++ b/composer.json
@@ -32,7 +32,7 @@
     },
     "require-dev": {
         "clue/stream-filter": "^1.2",
-        "phpstan/phpstan": "1.11.1 || 1.4.10",
+        "phpstan/phpstan": "1.12.19 || 1.4.10",
         "phpunit/phpunit": "^9.6 || ^7.5"
     },
     "autoload": {