diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 05e7b40..3584e6c 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -31,4 +31,4 @@ jobs:
       os: >-
         ['ubuntu-latest', 'windows-latest']
       php: >-
-        ['8.1', '8.2', '8.3']
+        ['8.1', '8.2', '8.3', '8.4']
diff --git a/.github/workflows/composer-require-checker.yml b/.github/workflows/composer-require-checker.yml
index a857bce..a93390b 100644
--- a/.github/workflows/composer-require-checker.yml
+++ b/.github/workflows/composer-require-checker.yml
@@ -31,4 +31,4 @@ jobs:
       os: >-
         ['ubuntu-latest']
       php: >-
-        ['8.1', '8.2', '8.3']
+        ['8.1', '8.2', '8.3', '8.4']
diff --git a/.github/workflows/mutation.yml b/.github/workflows/mutation.yml
index a6873e2..a56769e 100644
--- a/.github/workflows/mutation.yml
+++ b/.github/workflows/mutation.yml
@@ -27,6 +27,6 @@ jobs:
       os: >-
         ['ubuntu-latest']
       php: >-
-        ['8.3']
+        ['8.4']
     secrets:
       STRYKER_DASHBOARD_API_KEY: ${{ secrets.STRYKER_DASHBOARD_API_KEY }}
diff --git a/.github/workflows/rector.yml b/.github/workflows/rector.yml
index 457772a..5d6931d 100644
--- a/.github/workflows/rector.yml
+++ b/.github/workflows/rector.yml
@@ -21,4 +21,4 @@ jobs:
       os: >-
         ['ubuntu-latest']
       php: >-
-        ['8.3']
+        ['8.4']
diff --git a/.github/workflows/static.yml b/.github/workflows/static.yml
index e33eca8..d03874d 100644
--- a/.github/workflows/static.yml
+++ b/.github/workflows/static.yml
@@ -29,4 +29,4 @@ jobs:
       os: >-
         ['ubuntu-latest']
       php: >-
-        ['8.1', '8.2', '8.3']
+        ['8.1', '8.2', '8.3', '8.4']
diff --git a/CHANGELOG.md b/CHANGELOG.md
index d2870f0..914648d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,7 +2,8 @@
 
 ## 3.2.1 under development
 
-- Сhg #90: Bump minimal required PHP version to 8.1 and minor refactoring (@vjik)
+- Chg #91: Change PHP constraint in `composer.json` to `~8.1.0 || ~8.2.0 || ~8.3.0 || ~8.4.0` (@vjik)
+- Сhg #90, #91: Bump minimal required PHP version to 8.1 and minor refactoring (@vjik)
 
 ## 3.2.0 January 13, 2025
 
diff --git a/README.md b/README.md
index 1a66f35..02168f9 100644
--- a/README.md
+++ b/README.md
@@ -18,7 +18,7 @@ This package implements file-based [PSR-16](https://www.php-fig.org/psr/psr-16/)
 
 ## Requirements
 
-- PHP 8.0 or higher.
+- PHP 8.1 or higher.
 
 ## Installation
 
diff --git a/composer.json b/composer.json
index 26001dc..e17170a 100644
--- a/composer.json
+++ b/composer.json
@@ -30,8 +30,8 @@
         }
     ],
     "require": {
-        "php": "^8.1",
-        "psr/simple-cache": "^2.0|^3.0"
+        "php": "~8.1.0 || ~8.2.0 || ~8.3.0 || ~8.4.0",
+        "psr/simple-cache": "^2.0 || ^3.0"
     },
     "require-dev": {
         "maglnet/composer-require-checker": "^4.7.1",
@@ -40,7 +40,7 @@
         "rector/rector": "^2.0.9",
         "roave/infection-static-analysis-plugin": "^1.35",
         "spatie/phpunit-watcher": "^1.24",
-        "vimeo/psalm": "^5.26.1",
+        "vimeo/psalm": "^5.21 || ^6.5.1",
         "yiisoft/aliases": "^3.0",
         "yiisoft/di": "^1.3"
     },
diff --git a/src/FileCache.php b/src/FileCache.php
index e65619d..b866638 100644
--- a/src/FileCache.php
+++ b/src/FileCache.php
@@ -91,7 +91,7 @@ final class FileCache implements CacheInterface
      * @throws CacheException If failed to create cache directory.
      */
     public function __construct(
-        private string $cachePath,
+        private readonly string $cachePath,
         private int $directoryMode = 0775,
     ) {
     }
@@ -106,6 +106,9 @@ public function get(string $key, mixed $default = null): mixed
         }
 
         flock($filePointer, LOCK_SH);
+        /**
+         * @var string $value We assume that we always can read content from `$filePointer` resource.
+         */
         $value = stream_get_contents($filePointer);
         flock($filePointer, LOCK_UN);
         fclose($filePointer);