diff --git a/phpstan-baseline.php b/phpstan-baseline.php
index 6d22593ffcab..16da2877e0a3 100644
--- a/phpstan-baseline.php
+++ b/phpstan-baseline.php
@@ -716,76 +716,6 @@
 	'count' => 1,
 	'path' => __DIR__ . '/system/Database/Seeder.php',
 ];
-$ignoreErrors[] = [
-	'message' => '#^Method CodeIgniter\\\\Debug\\\\Exceptions\\:\\:exceptionHandler\\(\\) has no return type specified\\.$#',
-	'count' => 1,
-	'path' => __DIR__ . '/system/Debug/Exceptions.php',
-];
-$ignoreErrors[] = [
-	'message' => '#^Method CodeIgniter\\\\Debug\\\\Exceptions\\:\\:initialize\\(\\) has no return type specified\\.$#',
-	'count' => 1,
-	'path' => __DIR__ . '/system/Debug/Exceptions.php',
-];
-$ignoreErrors[] = [
-	'message' => '#^Method CodeIgniter\\\\Debug\\\\Exceptions\\:\\:render\\(\\) has no return type specified\\.$#',
-	'count' => 1,
-	'path' => __DIR__ . '/system/Debug/Exceptions.php',
-];
-$ignoreErrors[] = [
-	'message' => '#^Method CodeIgniter\\\\Debug\\\\Exceptions\\:\\:shutdownHandler\\(\\) has no return type specified\\.$#',
-	'count' => 1,
-	'path' => __DIR__ . '/system/Debug/Exceptions.php',
-];
-$ignoreErrors[] = [
-	'message' => '#^Method CodeIgniter\\\\Debug\\\\Iterator\\:\\:add\\(\\) has parameter \\$closure with no signature specified for Closure\\.$#',
-	'count' => 1,
-	'path' => __DIR__ . '/system/Debug/Iterator.php',
-];
-$ignoreErrors[] = [
-	'message' => '#^Method CodeIgniter\\\\Debug\\\\Timer\\:\\:record\\(\\) has parameter \\$callable with no signature specified for callable\\.$#',
-	'count' => 1,
-	'path' => __DIR__ . '/system/Debug/Timer.php',
-];
-$ignoreErrors[] = [
-	'message' => '#^Method CodeIgniter\\\\Debug\\\\Toolbar\\:\\:prepare\\(\\) has no return type specified\\.$#',
-	'count' => 1,
-	'path' => __DIR__ . '/system/Debug/Toolbar.php',
-];
-$ignoreErrors[] = [
-	'message' => '#^Method CodeIgniter\\\\Debug\\\\Toolbar\\:\\:respond\\(\\) has no return type specified\\.$#',
-	'count' => 1,
-	'path' => __DIR__ . '/system/Debug/Toolbar.php',
-];
-$ignoreErrors[] = [
-	'message' => '#^Method CodeIgniter\\\\Debug\\\\Toolbar\\\\Collectors\\\\BaseCollector\\:\\:getBadgeValue\\(\\) has no return type specified\\.$#',
-	'count' => 1,
-	'path' => __DIR__ . '/system/Debug/Toolbar/Collectors/BaseCollector.php',
-];
-$ignoreErrors[] = [
-	'message' => '#^Method CodeIgniter\\\\Debug\\\\Toolbar\\\\Collectors\\\\BaseCollector\\:\\:getVarData\\(\\) has no return type specified\\.$#',
-	'count' => 1,
-	'path' => __DIR__ . '/system/Debug/Toolbar/Collectors/BaseCollector.php',
-];
-$ignoreErrors[] = [
-	'message' => '#^Method CodeIgniter\\\\Debug\\\\Toolbar\\\\Collectors\\\\Database\\:\\:collect\\(\\) has no return type specified\\.$#',
-	'count' => 1,
-	'path' => __DIR__ . '/system/Debug/Toolbar/Collectors/Database.php',
-];
-$ignoreErrors[] = [
-	'message' => '#^Method CodeIgniter\\\\Debug\\\\Toolbar\\\\Collectors\\\\Database\\:\\:getConnections\\(\\) has no return type specified\\.$#',
-	'count' => 1,
-	'path' => __DIR__ . '/system/Debug/Toolbar/Collectors/Database.php',
-];
-$ignoreErrors[] = [
-	'message' => '#^Method CodeIgniter\\\\Debug\\\\Toolbar\\\\Collectors\\\\History\\:\\:setFiles\\(\\) has no return type specified\\.$#',
-	'count' => 1,
-	'path' => __DIR__ . '/system/Debug/Toolbar/Collectors/History.php',
-];
-$ignoreErrors[] = [
-	'message' => '#^Method CodeIgniter\\\\Debug\\\\Toolbar\\\\Collectors\\\\Logs\\:\\:collectLogs\\(\\) has no return type specified\\.$#',
-	'count' => 1,
-	'path' => __DIR__ . '/system/Debug/Toolbar/Collectors/Logs.php',
-];
 $ignoreErrors[] = [
 	'message' => '#^Property CodeIgniter\\\\Log\\\\Logger\\:\\:\\$logCache \\(array\\) on left side of \\?\\? is not nullable\\.$#',
 	'count' => 1,
diff --git a/system/Debug/Exceptions.php b/system/Debug/Exceptions.php
index 6df81c16d5a5..77f5736d28a3 100644
--- a/system/Debug/Exceptions.php
+++ b/system/Debug/Exceptions.php
@@ -98,6 +98,8 @@ public function __construct(ExceptionsConfig $config, $request, ResponseInterfac
      * handling of our application.
      *
      * @codeCoverageIgnore
+     *
+     * @return void
      */
     public function initialize()
     {
@@ -112,6 +114,9 @@ public function initialize()
      * and fire an event that allows custom actions to be taken at this point.
      *
      * @codeCoverageIgnore
+     *
+     * @return void
+     * @phpstan-return never|void
      */
     public function exceptionHandler(Throwable $exception)
     {
@@ -189,6 +194,9 @@ public function errorHandler(int $severity, string $message, ?string $file = nul
      * need to be caught and handle them.
      *
      * @codeCoverageIgnore
+     *
+     * @return void
+     * @phpstan-return never|void
      */
     public function shutdownHandler()
     {
@@ -243,6 +251,9 @@ protected function determineView(Throwable $exception, string $templatePath): st
 
     /**
      * Given an exception and status code will display the error to the client.
+     *
+     * @return void
+     * @phpstan-return never|void
      */
     protected function render(Throwable $exception, int $statusCode)
     {
diff --git a/system/Debug/Iterator.php b/system/Debug/Iterator.php
index 62343745b17b..f54335b6dd70 100644
--- a/system/Debug/Iterator.php
+++ b/system/Debug/Iterator.php
@@ -38,6 +38,8 @@ class Iterator
      * Tests are simply closures that the user can define any sequence of
      * things to happen during the test.
      *
+     * @phpstan-param Closure(): mixed $closure
+     *
      * @return $this
      */
     public function add(string $name, Closure $closure)
diff --git a/system/Debug/Timer.php b/system/Debug/Timer.php
index 68a9b7898c64..216b10bab758 100644
--- a/system/Debug/Timer.php
+++ b/system/Debug/Timer.php
@@ -131,8 +131,8 @@ public function has(string $name): bool
      * Executes callable and measures its time.
      * Returns its return value if any.
      *
-     * @param string   $name     The name of the timer
-     * @param callable $callable callable to be executed
+     * @param string $name The name of the timer
+     * @phpstan-param callable(): mixed $callable callable to be executed
      *
      * @return array|bool|float|int|object|resource|string|null
      */
diff --git a/system/Debug/Toolbar.php b/system/Debug/Toolbar.php
index f00ad09bd122..d20125b9b5bd 100644
--- a/system/Debug/Toolbar.php
+++ b/system/Debug/Toolbar.php
@@ -348,6 +348,8 @@ protected function roundTo(float $number, int $increments = 5): float
      *
      * @param RequestInterface  $request
      * @param ResponseInterface $response
+     *
+     * @return void
      */
     public function prepare(?RequestInterface $request = null, ?ResponseInterface $response = null)
     {
@@ -434,6 +436,9 @@ public function prepare(?RequestInterface $request = null, ?ResponseInterface $r
      * Inject debug toolbar into the response.
      *
      * @codeCoverageIgnore
+     *
+     * @return void
+     * @phpstan-return never|void
      */
     public function respond()
     {
diff --git a/system/Debug/Toolbar/Collectors/BaseCollector.php b/system/Debug/Toolbar/Collectors/BaseCollector.php
index e8aaad9ba115..4704fcdcaaeb 100644
--- a/system/Debug/Toolbar/Collectors/BaseCollector.php
+++ b/system/Debug/Toolbar/Collectors/BaseCollector.php
@@ -137,6 +137,8 @@ public function hasVarData(): bool
      *          'bar' => 'baz'
      *      ],
      *  ];
+     *
+     * @return array|null
      */
     public function getVarData()
     {
@@ -183,6 +185,8 @@ public function cleanPath(string $file): string
 
     /**
      * Gets the "badge" value for the button.
+     *
+     * @return int|null
      */
     public function getBadgeValue()
     {
diff --git a/system/Debug/Toolbar/Collectors/Database.php b/system/Debug/Toolbar/Collectors/Database.php
index 5cb285b95554..f487af59cef4 100644
--- a/system/Debug/Toolbar/Collectors/Database.php
+++ b/system/Debug/Toolbar/Collectors/Database.php
@@ -76,6 +76,9 @@ public function __construct()
      * data.
      *
      * @internal
+     *
+     * @return void
+     * @phpstan-return never|void
      */
     public static function collect(Query $query)
     {
@@ -247,7 +250,7 @@ public function icon(): string
     /**
      * Gets the connections from the database config
      */
-    private function getConnections()
+    private function getConnections(): void
     {
         $this->connections = \Config\Database::getConnections();
     }
diff --git a/system/Debug/Toolbar/Collectors/History.php b/system/Debug/Toolbar/Collectors/History.php
index afc68ee85f2e..9645bd91863a 100644
--- a/system/Debug/Toolbar/Collectors/History.php
+++ b/system/Debug/Toolbar/Collectors/History.php
@@ -60,6 +60,8 @@ class History extends BaseCollector
      *
      * @param string $current Current history time
      * @param int    $limit   Max history files
+     *
+     * @return void
      */
     public function setFiles(string $current, int $limit = 20)
     {
diff --git a/system/Debug/Toolbar/Collectors/Logs.php b/system/Debug/Toolbar/Collectors/Logs.php
index 42d7307ab9d1..d656ca9bcefb 100644
--- a/system/Debug/Toolbar/Collectors/Logs.php
+++ b/system/Debug/Toolbar/Collectors/Logs.php
@@ -81,6 +81,8 @@ public function icon(): string
 
     /**
      * Ensures the data has been collected.
+     *
+     * @return array
      */
     protected function collectLogs()
     {