diff --git a/.github/workflows/continuous-integration.yml b/.github/workflows/continuous-integration.yml
index 6077d60..4d4da05 100644
--- a/.github/workflows/continuous-integration.yml
+++ b/.github/workflows/continuous-integration.yml
@@ -8,7 +8,7 @@ jobs:
     strategy:
       matrix:
         operating-system: [ubuntu-latest]
-        php-versions: ['7.4', '8.0', '8.1', '8.2']
+        php-versions: ['7.4', '8.0', '8.1', '8.2', '8.3', '8.4']
     name: PHP ${{ matrix.php-versions }} Test on ${{ matrix.operating-system }}
     steps:
       - uses: actions/checkout@v3
@@ -33,4 +33,4 @@ jobs:
       
       - name: Upload code coverage data
         if: ${{ matrix.php-versions == '7.4' }}
-        run: php vendor/bin/ocular code-coverage:upload --format=php-clover coverage.clover
\ No newline at end of file
+        run: php vendor/bin/ocular code-coverage:upload --format=php-clover coverage.clover
diff --git a/CHANGELOG.md b/CHANGELOG.md
index f04acd0..6029a6b 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,16 @@
 
 All notable changes to `Config` will be documented in this file
 
+## 3.2.0 - 2024-12-09
+
+### Added
+* PHP 8.3 and 8.4 to the build matrix (#164)
+
+### Fixed
+* Fatal error when root is null in has() method (#159 and #160)
+* PHP 8.4 deprecations implicitly marking parameter as nullable is deprecated (#163)
+
+
 ## 3.1.0 - 2022-12-20
 
 ### Added
diff --git a/src/AbstractConfig.php b/src/AbstractConfig.php
index 5932eda..340ddf4 100644
--- a/src/AbstractConfig.php
+++ b/src/AbstractConfig.php
@@ -123,7 +123,7 @@ public function has($key)
 
         // nested case
         foreach ($segments as $segment) {
-            if (array_key_exists($segment, $root)) {
+            if (is_array($root) && array_key_exists($segment, $root)) {
                 $root = $root[$segment];
                 continue;
             } else {
diff --git a/src/Config.php b/src/Config.php
index 8838e44..dad3b67 100644
--- a/src/Config.php
+++ b/src/Config.php
@@ -67,10 +67,10 @@ public static function load($values, $parser = null, $string = false)
      * Loads a Config instance.
      *
      * @param  string|array    $values Filenames or string with configuration
-     * @param  ParserInterface $parser Configuration parser
+     * @param  ?ParserInterface $parser Configuration parser
      * @param  bool            $string Enable loading from string
      */
-    public function __construct($values, ParserInterface $parser = null, $string = false)
+    public function __construct($values, ?ParserInterface $parser = null, $string = false)
     {
         if ($string === true) {
             $this->loadFromString($values, $parser);
@@ -85,11 +85,11 @@ public function __construct($values, ParserInterface $parser = null, $string = f
      * Loads configuration from file.
      *
      * @param  string|array     $path   Filenames or directories with configuration
-     * @param  ParserInterface  $parser Configuration parser
+     * @param  ?ParserInterface $parser Configuration parser
      *
      * @throws EmptyDirectoryException If `$path` is an empty directory
      */
-    protected function loadFromFile($path, ParserInterface $parser = null)
+    protected function loadFromFile($path, ?ParserInterface $parser = null)
     {
         $paths      = $this->getValidPath($path);
         $this->data = [];
@@ -125,11 +125,11 @@ protected function loadFromFile($path, ParserInterface $parser = null)
      * Writes configuration to file.
      *
      * @param  string           $filename   Filename to save configuration to
-     * @param  WriterInterface  $writer Configuration writer
+     * @param  ?WriterInterface $writer Configuration writer
      *
      * @throws WriteException if the data could not be written to the file
      */
-    public function toFile($filename, WriterInterface $writer = null)
+    public function toFile($filename, ?WriterInterface $writer = null)
     {
         if ($writer === null) {
             // Get file information
diff --git a/tests/AbstractConfigTest.php b/tests/AbstractConfigTest.php
index 551d246..e0fe945 100644
--- a/tests/AbstractConfigTest.php
+++ b/tests/AbstractConfigTest.php
@@ -247,6 +247,7 @@ public function testHasNestedKey()
         $this->assertTrue($this->config->has('application.runtime'));
         $this->assertFalse($this->config->has('application.not_exist'));
         $this->assertFalse($this->config->has('not_exist.name'));
+        $this->assertFalse($this->config->has('application.name.not_exist'));
     }
 
     /**