diff --git a/app/Views/errors/cli/error_exception.php b/app/Views/errors/cli/error_exception.php
index 49bcd89131fb..e908b426381d 100644
--- a/app/Views/errors/cli/error_exception.php
+++ b/app/Views/errors/cli/error_exception.php
@@ -14,7 +14,7 @@
     $last = $prevException;
 
     CLI::write('  Caused by:');
-    CLI::write('  [' . get_class($prevException) . ']', 'red');
+    CLI::write('  [' . $prevException::class . ']', 'red');
     CLI::write('  ' . $prevException->getMessage());
     CLI::write('  at ' . CLI::color(clean_path($prevException->getFile()) . ':' . $prevException->getLine(), 'green'));
     CLI::newLine();
diff --git a/app/Views/errors/html/error_exception.php b/app/Views/errors/html/error_exception.php
index 2e5571e97e4b..7f4717d4f291 100644
--- a/app/Views/errors/html/error_exception.php
+++ b/app/Views/errors/html/error_exception.php
@@ -55,10 +55,10 @@
 
     <pre>
     Caused by:
-    <?= esc(get_class($prevException)), esc($prevException->getCode() ? ' #' . $prevException->getCode() : '') ?>
+    <?= esc($prevException::class), esc($prevException->getCode() ? ' #' . $prevException->getCode() : '') ?>
 
     <?= nl2br(esc($prevException->getMessage())) ?>
-    <a href="https://www.duckduckgo.com/?q=<?= urlencode(get_class($prevException) . ' ' . preg_replace('#\'.*\'|".*"#Us', '', $prevException->getMessage())) ?>"
+    <a href="https://www.duckduckgo.com/?q=<?= urlencode($prevException::class . ' ' . preg_replace('#\'.*\'|".*"#Us', '', $prevException->getMessage())) ?>"
        rel="noreferrer" target="_blank">search &rarr;</a>
     <?= esc(clean_path($prevException->getFile()) . ':' . $prevException->getLine()) ?>
     </pre>
diff --git a/system/CLI/InputOutput.php b/system/CLI/InputOutput.php
index 5b6c1da02f4d..b69c19e2eee1 100644
--- a/system/CLI/InputOutput.php
+++ b/system/CLI/InputOutput.php
@@ -21,7 +21,7 @@ class InputOutput
     /**
      * Is the readline library on the system?
      */
-    private bool $readlineSupport;
+    private readonly bool $readlineSupport;
 
     public function __construct()
     {
diff --git a/system/Commands/Utilities/Routes/SampleURIGenerator.php b/system/Commands/Utilities/Routes/SampleURIGenerator.php
index 4c4cf0c9112e..c0832a382eff 100644
--- a/system/Commands/Utilities/Routes/SampleURIGenerator.php
+++ b/system/Commands/Utilities/Routes/SampleURIGenerator.php
@@ -52,7 +52,7 @@ public function get(string $routeKey): string
     {
         $sampleUri = $routeKey;
 
-        if (strpos($routeKey, '{locale}') !== false) {
+        if (str_contains($routeKey, '{locale}')) {
             $sampleUri = str_replace(
                 '{locale}',
                 config(App::class)->defaultLocale,
diff --git a/system/Debug/Exceptions.php b/system/Debug/Exceptions.php
index 2ae5890c6acb..dfb5b81bd7bd 100644
--- a/system/Debug/Exceptions.php
+++ b/system/Debug/Exceptions.php
@@ -130,7 +130,7 @@ public function exceptionHandler(Throwable $exception)
             $uri       = $this->request->getPath() === '' ? '/' : $this->request->getPath();
             $routeInfo = '[Method: ' . $this->request->getMethod() . ', Route: ' . $uri . ']';
 
-            log_message('critical', get_class($exception) . ": {message}\n{routeInfo}\nin {exFile} on line {exLine}.\n{trace}", [
+            log_message('critical', $exception::class . ": {message}\n{routeInfo}\nin {exFile} on line {exLine}.\n{trace}", [
                 'message'   => $exception->getMessage(),
                 'routeInfo' => $routeInfo,
                 'exFile'    => clean_path($exception->getFile()), // {file} refers to THIS file
@@ -144,7 +144,7 @@ public function exceptionHandler(Throwable $exception)
             while ($prevException = $last->getPrevious()) {
                 $last = $prevException;
 
-                log_message('critical', '[Caused by] ' . get_class($prevException) . ": {message}\nin {exFile} on line {exLine}.\n{trace}", [
+                log_message('critical', '[Caused by] ' . $prevException::class . ": {message}\nin {exFile} on line {exLine}.\n{trace}", [
                     'message' => $prevException->getMessage(),
                     'exFile'  => clean_path($prevException->getFile()), // {file} refers to THIS file
                     'exLine'  => $prevException->getLine(), // {line} refers to THIS line
diff --git a/system/Filters/Filters.php b/system/Filters/Filters.php
index 6816e72ab482..acfc9970c522 100644
--- a/system/Filters/Filters.php
+++ b/system/Filters/Filters.php
@@ -230,7 +230,7 @@ private function runAfter(array $filterClasses): ResponseInterface
             $class = new $className();
 
             if (! $class instanceof FilterInterface) {
-                throw FilterException::forIncorrectInterface(get_class($class));
+                throw FilterException::forIncorrectInterface($class::class);
             }
 
             $result = $class->after(
diff --git a/system/Filters/PageCache.php b/system/Filters/PageCache.php
index d6fa407f5a0d..c3bb2af90dd6 100644
--- a/system/Filters/PageCache.php
+++ b/system/Filters/PageCache.php
@@ -25,7 +25,7 @@
  */
 class PageCache implements FilterInterface
 {
-    private ResponseCache $pageCache;
+    private readonly ResponseCache $pageCache;
 
     public function __construct()
     {
diff --git a/system/HTTP/Method.php b/system/HTTP/Method.php
index 7aae162b3cba..6ad3847cc2f7 100644
--- a/system/HTTP/Method.php
+++ b/system/HTTP/Method.php
@@ -19,59 +19,59 @@ class Method
     /**
      * @see https://developer.mozilla.org/en-US/docs/Web/HTTP/Methods/CONNECT
      */
-    public const CONNECT = 'CONNECT';
+    final public const CONNECT = 'CONNECT';
 
     /**
      * Idempotent
      *
      * @see https://developer.mozilla.org/en-US/docs/Web/HTTP/Methods/DELETE
      */
-    public const DELETE = 'DELETE';
+    final public const DELETE = 'DELETE';
 
     /**
      * Safe, Idempotent, Cacheable
      *
      * @see https://developer.mozilla.org/en-US/docs/Web/HTTP/Methods/GET
      */
-    public const GET = 'GET';
+    final public const GET = 'GET';
 
     /**
      * Safe, Idempotent, Cacheable
      *
      * @see https://developer.mozilla.org/en-US/docs/Web/HTTP/Methods/HEAD
      */
-    public const HEAD = 'HEAD';
+    final public const HEAD = 'HEAD';
 
     /**
      * Safe, Idempotent
      *
      * @see https://developer.mozilla.org/en-US/docs/Web/HTTP/Methods/OPTIONS
      */
-    public const OPTIONS = 'OPTIONS';
+    final public const OPTIONS = 'OPTIONS';
 
     /**
      * @see https://developer.mozilla.org/en-US/docs/Web/HTTP/Methods/PATCH
      */
-    public const PATCH = 'PATCH';
+    final public const PATCH = 'PATCH';
 
     /**
      * @see https://developer.mozilla.org/en-US/docs/Web/HTTP/Methods/POST
      */
-    public const POST = 'POST';
+    final public const POST = 'POST';
 
     /**
      * Idempotent
      *
      * @see https://developer.mozilla.org/en-US/docs/Web/HTTP/Methods/PUT
      */
-    public const PUT = 'PUT';
+    final public const PUT = 'PUT';
 
     /**
      * Safe, Idempotent
      *
      * @see https://developer.mozilla.org/en-US/docs/Web/HTTP/Methods/TRACE
      */
-    public const TRACE = 'TRACE';
+    final public const TRACE = 'TRACE';
 
     /**
      * Returns all HTTP methods.
diff --git a/system/Router/Router.php b/system/Router/Router.php
index e7b0c087c07d..54005c812cd9 100644
--- a/system/Router/Router.php
+++ b/system/Router/Router.php
@@ -30,7 +30,7 @@ class Router implements RouterInterface
     /**
      * List of allowed HTTP methods (and CLI for command line use).
      */
-    public const HTTP_METHODS = [
+    final public const HTTP_METHODS = [
         Method::GET,
         Method::HEAD,
         Method::POST,
diff --git a/system/Validation/Rules.php b/system/Validation/Rules.php
index 00a4480676f4..d0c609e84699 100644
--- a/system/Validation/Rules.php
+++ b/system/Validation/Rules.php
@@ -444,7 +444,7 @@ public function field_exists(
         ?string $error = null,
         ?string $field = null
     ): bool {
-        if (strpos($field, '.') !== false) {
+        if (str_contains($field, '.')) {
             return ArrayHelper::dotKeyExists($field, $data);
         }
 
diff --git a/system/Validation/StrictRules/Rules.php b/system/Validation/StrictRules/Rules.php
index 712200321764..abb0a6033c1f 100644
--- a/system/Validation/StrictRules/Rules.php
+++ b/system/Validation/StrictRules/Rules.php
@@ -44,7 +44,7 @@ public function differs(
         ?string $error = null,
         ?string $field = null
     ): bool {
-        if (strpos($otherField, '.') !== false) {
+        if (str_contains($otherField, '.')) {
             return $str !== dot_array_search($otherField, $data);
         }
 
@@ -275,7 +275,7 @@ public function matches(
         ?string $error = null,
         ?string $field = null
     ): bool {
-        if (strpos($otherField, '.') !== false) {
+        if (str_contains($otherField, '.')) {
             return $str === dot_array_search($otherField, $data);
         }
 
@@ -420,7 +420,7 @@ public function field_exists(
         ?string $error = null,
         ?string $field = null
     ): bool {
-        if (strpos($field, '.') !== false) {
+        if (str_contains($field, '.')) {
             return ArrayHelper::dotKeyExists($field, $data);
         }