diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index a398ff9..d7761a8 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
@@ -20,7 +21,7 @@ jobs:
           - 7.2
           - 7.1
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
       - uses: shivammathur/setup-php@v2
         with:
           php-version: ${{ matrix.php }}
@@ -34,10 +35,11 @@ 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
@@ -46,7 +48,7 @@ jobs:
           - 7.3
           - 7.2
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
       - uses: shivammathur/setup-php@v2
         with:
           php-version: ${{ matrix.php }}
diff --git a/composer.json b/composer.json
index 5d1e277..6bf687d 100644
--- a/composer.json
+++ b/composer.json
@@ -28,7 +28,7 @@
         "php": ">=7.1.0"
     },
     "require-dev": {
-        "phpstan/phpstan": "1.10.39 || 1.4.10",
+        "phpstan/phpstan": "1.12.28 || 1.4.10",
         "phpunit/phpunit": "^9.6 || ^7.5"
     },
     "autoload": {
diff --git a/src/Internal/FulfilledPromise.php b/src/Internal/FulfilledPromise.php
index 8664ffd..8a66cff 100644
--- a/src/Internal/FulfilledPromise.php
+++ b/src/Internal/FulfilledPromise.php
@@ -59,6 +59,7 @@ public function catch(callable $onRejected): PromiseInterface
     public function finally(callable $onFulfilledOrRejected): PromiseInterface
     {
         return $this->then(function ($value) use ($onFulfilledOrRejected): PromiseInterface {
+            /** @var T $value */
             return resolve($onFulfilledOrRejected())->then(function () use ($value) {
                 return $value;
             });
diff --git a/src/Promise.php b/src/Promise.php
index 4ac2700..0828674 100644
--- a/src/Promise.php
+++ b/src/Promise.php
@@ -97,6 +97,7 @@ public function catch(callable $onRejected): PromiseInterface
     public function finally(callable $onFulfilledOrRejected): PromiseInterface
     {
         return $this->then(static function ($value) use ($onFulfilledOrRejected): PromiseInterface {
+            /** @var T $value */
             return resolve($onFulfilledOrRejected())->then(function () use ($value) {
                 return $value;
             });
diff --git a/tests/FunctionSetRejectionHandlerThatTriggersDefaultHandlerShouldTerminateProgramForUnhandled.phpt b/tests/FunctionSetRejectionHandlerThatTriggersDefaultHandlerShouldTerminateProgramForUnhandled.phpt
index 14b5c7c..3406968 100644
--- a/tests/FunctionSetRejectionHandlerThatTriggersDefaultHandlerShouldTerminateProgramForUnhandled.phpt
+++ b/tests/FunctionSetRejectionHandlerThatTriggersDefaultHandlerShouldTerminateProgramForUnhandled.phpt
@@ -1,5 +1,7 @@
 --TEST--
 The callback given to set_rejection_handler() may trigger a fatal error for unhandled rejection
+--SKIPIF--
+<?php if (PHP_VERSION_ID >= 80400) die("Skipped: PHP < 8.4 only."); ?>
 --INI--
 # suppress legacy PHPUnit 7 warning for Xdebug 3
 xdebug.default_enable=