diff --git a/.github/workflows/Tests.yml b/.github/workflows/Tests.yml
index 24bf72e5..fb368d35 100644
--- a/.github/workflows/Tests.yml
+++ b/.github/workflows/Tests.yml
@@ -10,7 +10,7 @@ jobs:
         strategy:
             fail-fast: true
             matrix:
-                php-versions: ['8.0', '8.1', '8.2', '8.3']
+                php-versions: ['8.0', '8.1', '8.2', '8.3', '8.4']
 
         steps:
             -   name: Checkout
@@ -41,7 +41,7 @@ jobs:
         strategy:
             fail-fast: true
             matrix:
-                php-versions: ['8.0', '8.1', '8.2', '8.3']
+                php-versions: ['8.0', '8.1', '8.2', '8.3', '8.4']
 
         steps:
             -   name: Checkout
diff --git a/lib/Http/Response.php b/lib/Http/Response.php
index 57651fe3..db93db2c 100644
--- a/lib/Http/Response.php
+++ b/lib/Http/Response.php
@@ -298,7 +298,11 @@ public static function fromString($responseStr)
             throw new Exception('Failed to parse HTTP response status line.');
         }
 
-        // Process the rest of the header lines
+        /**
+         * Process the rest of the header lines
+         *
+         * @var array<string,array<mixed>>
+         */
         $headers = [];
         foreach ($headerLines as $line) {
             if (preg_match("|^([\w-]+):\s+(.+)$|", $line, $m)) {
@@ -306,7 +310,7 @@ public static function fromString($responseStr)
                 $hValue = $m[2];
 
                 if (isset($headers[$hName])) {
-                    if (!\is_array($headers[$hName])) {
+                    if (false === \is_array($headers[$hName])) {
                         $headers[$hName] = [$headers[$hName]];
                     }
                     $headers[$hName][] = $hValue;
diff --git a/lib/ParsedUri.php b/lib/ParsedUri.php
index a9f9efe2..4cdfdc41 100644
--- a/lib/ParsedUri.php
+++ b/lib/ParsedUri.php
@@ -69,6 +69,17 @@ public function __construct($uri = null)
     {
         if (\is_string($uri)) {
             if (preg_match(self::URI_REGEX, $uri, $matches)) {
+                /**
+                 * Without the following "hack", PHPStan would throw the following errors (PHP 8.4):
+                 *
+                 * 74   Offset 2 on array{0: string, 1: string, 2: string, ...} in isset() always exists and is not nullable.
+                 * 80   Offset 4 on array{0: string, 1: string, 2: string, ...} in isset() always exists and is not nullable.
+                 * 86   Offset 5 on array{0: string, 1: string, 2: string, ...} in isset() always exists and is not nullable.
+                 *
+                 * @var array<mixed>
+                 */
+                $matches = $matches;
+
                 if (!empty($matches[1])) {
                     $this->scheme = isset($matches[2]) ? $matches[2] : '';
                 }
diff --git a/lib/Parser/RdfXml.php b/lib/Parser/RdfXml.php
index b5822500..e8f3422c 100644
--- a/lib/Parser/RdfXml.php
+++ b/lib/Parser/RdfXml.php
@@ -94,7 +94,6 @@ protected function initXMLParser()
             xml_set_element_handler($parser, [$this, 'startElementHandler'], [$this, 'endElementHandler']);
             xml_set_character_data_handler($parser, [$this, 'cdataHandler']);
             xml_set_start_namespace_decl_handler($parser, [$this, 'newNamespaceHandler']);
-            xml_set_object($parser, $this);
             $this->xmlParser = $parser;
         }
     }