diff --git a/system/Database/Database.php b/system/Database/Database.php
index 4cb5dfaf1627..d84d65482536 100644
--- a/system/Database/Database.php
+++ b/system/Database/Database.php
@@ -58,7 +58,7 @@ public function load(array $params = [], string $alias = '')
             throw new InvalidArgumentException('You have not selected a database type to connect to.');
         }
 
-        assert($this->checkDbExtension($params['DBDriver']));
+        $this->checkDbExtension($params['DBDriver']);
 
         $this->connections[$alias] = $this->initDriver($params['DBDriver'], 'Connection', $params);
 
@@ -158,11 +158,11 @@ protected function initDriver(string $driver, string $class, $argument): object
      *
      * @param string $driver DB driver or FQCN for custom driver
      */
-    private function checkDbExtension(string $driver): bool
+    private function checkDbExtension(string $driver): void
     {
         if (str_contains($driver, '\\')) {
             // Cannot check a fully qualified classname for a custom driver.
-            return true;
+            return;
         }
 
         $extensionMap = [
@@ -183,7 +183,7 @@ private function checkDbExtension(string $driver): bool
         }
 
         if (extension_loaded($extension)) {
-            return true;
+            return;
         }
 
         $message = 'The required PHP extension "' . $extension . '" is not loaded.'
diff --git a/system/HTTP/Files/FileCollection.php b/system/HTTP/Files/FileCollection.php
index 058e86c3a4aa..c1c0582f6ff5 100644
--- a/system/HTTP/Files/FileCollection.php
+++ b/system/HTTP/Files/FileCollection.php
@@ -189,7 +189,7 @@ protected function createFileObject(array $array)
 
         return new UploadedFile(
             $array['tmp_name'] ?? null,
-            $array['name'] ?? null,
+            $array['name'],
             $array['type'] ?? null,
             ($array['size'] ?? null) === null ? null : (int) $array['size'],
             $array['error'] ?? null,
diff --git a/system/HTTP/SiteURIFactory.php b/system/HTTP/SiteURIFactory.php
index 73cc9fe84ee4..11dccce6c540 100644
--- a/system/HTTP/SiteURIFactory.php
+++ b/system/HTTP/SiteURIFactory.php
@@ -227,7 +227,7 @@ private function createURIFromRoutePath(string $routePath): SiteURI
      */
     private function getHost(): ?string
     {
-        $httpHostPort = $this->superglobals->server('HTTP_HOST') ?? null;
+        $httpHostPort = $this->superglobals->server('HTTP_HOST');
 
         if ($httpHostPort !== null) {
             [$httpHost] = explode(':', $httpHostPort, 2);
diff --git a/system/Helpers/Array/ArrayHelper.php b/system/Helpers/Array/ArrayHelper.php
index f70f6905ca5d..d370e1f1112f 100644
--- a/system/Helpers/Array/ArrayHelper.php
+++ b/system/Helpers/Array/ArrayHelper.php
@@ -324,7 +324,7 @@ public static function recursiveCount(array $array, int $counter = 0): int
      * @param list<int|list<int|string>|string> $array
      * @param int|string|null                   $sortByIndex
      */
-    public static function sortValuesByNatural(array &$array, $sortByIndex = null): bool
+    public static function sortValuesByNatural(array &$array, $sortByIndex = null): true
     {
         return usort($array, static function ($currentValue, $nextValue) use ($sortByIndex): int {
             if ($sortByIndex !== null) {
diff --git a/system/Router/RouteCollection.php b/system/Router/RouteCollection.php
index 6ade80e6f9fc..c08c01530b79 100644
--- a/system/Router/RouteCollection.php
+++ b/system/Router/RouteCollection.php
@@ -1520,7 +1520,7 @@ private function checkSubdomains($subdomains): bool
 
         // Routes can be limited to any sub-domain. In that case, though,
         // it does require a sub-domain to be present.
-        if (! in_array($this->currentSubdomain, [null, ''], true) && in_array('*', $subdomains, true)) {
+        if ($this->currentSubdomain !== '' && in_array('*', $subdomains, true)) {
             return true;
         }