diff --git a/phpstan.neon.dist b/phpstan.neon.dist
index 63f562a13..5a406f846 100644
--- a/phpstan.neon.dist
+++ b/phpstan.neon.dist
@@ -23,3 +23,4 @@ parameters:
 		- APP_NAMESPACE
 		- CI_DEBUG
 		- ENVIRONMENT
+		- CodeIgniter\CodeIgniter::CI_VERSION
diff --git a/rector.php b/rector.php
index 4906a8213..1b797a7d0 100644
--- a/rector.php
+++ b/rector.php
@@ -23,7 +23,9 @@
 use Rector\Config\RectorConfig;
 use Rector\Core\ValueObject\PhpVersion;
 use Rector\DeadCode\Rector\ClassMethod\RemoveUnusedPromotedPropertyRector;
+use Rector\DeadCode\Rector\If_\UnwrapFutureCompatibleIfPhpVersionRector;
 use Rector\DeadCode\Rector\MethodCall\RemoveEmptyMethodCallRector;
+use Rector\DeadCode\Rector\Property\RemoveUnusedPrivatePropertyRector;
 use Rector\DeadCode\Rector\StmtsAwareInterface\RemoveJustPropertyFetchForAssignRector;
 use Rector\EarlyReturn\Rector\Foreach_\ChangeNestedForeachIfsToEarlyContinueRector;
 use Rector\EarlyReturn\Rector\If_\ChangeIfElseValueAssignToEarlyReturnRector;
@@ -108,6 +110,14 @@
         RemoveJustPropertyFetchForAssignRector::class => [
             __DIR__ . '/src/Models/UserModel.php',
         ],
+
+        // Ignore tests that use CodeIgniter::CI_VERSION
+        UnwrapFutureCompatibleIfPhpVersionRector::class => [
+            __DIR__ . '/tests/Commands/UserModelGeneratorTest.php',
+        ],
+        RemoveUnusedPrivatePropertyRector::class => [
+            __DIR__ . '/tests/Commands/UserModelGeneratorTest.php',
+        ],
     ]);
     // auto import fully qualified class names
     $rectorConfig->importNames();
diff --git a/src/Commands/Generators/UserModelGenerator.php b/src/Commands/Generators/UserModelGenerator.php
index fdb76596c..2e9680aa7 100644
--- a/src/Commands/Generators/UserModelGenerator.php
+++ b/src/Commands/Generators/UserModelGenerator.php
@@ -54,7 +54,7 @@ class UserModelGenerator extends BaseCommand
     /**
      * Actually execute the command.
      */
-    public function run(array $params): void
+    public function run(array $params): int
     {
         $this->component = 'Model';
         $this->directory = 'Models';
@@ -68,12 +68,15 @@ public function run(array $params): void
         if (! $this->verifyChosenModelClassName($class, $params)) {
             CLI::error('Cannot use `ShieldUserModel` as class name as this conflicts with the parent class.', 'light_gray', 'red');
 
-            return; // @TODO when CI4 is at v4.3+, change this to `return 1;` to signify failing exit
+            return 1;
         }
 
         $params[0] = $class;
 
-        $this->execute($params);
+        // @TODO execute() is deprecated in CI v4.3.0.
+        $this->execute($params); // @phpstan-ignore-line suppress deprecated error.
+
+        return 0;
     }
 
     /**
diff --git a/tests/Commands/UserModelGeneratorTest.php b/tests/Commands/UserModelGeneratorTest.php
index cf009e373..d7fbfd522 100644
--- a/tests/Commands/UserModelGeneratorTest.php
+++ b/tests/Commands/UserModelGeneratorTest.php
@@ -4,6 +4,7 @@
 
 namespace Tests\Commands;
 
+use CodeIgniter\CodeIgniter;
 use CodeIgniter\Test\CIUnitTestCase;
 use CodeIgniter\Test\Filters\CITestStreamFilter;
 
@@ -18,10 +19,16 @@ protected function setUp(): void
     {
         parent::setUp();
 
-        CITestStreamFilter::$buffer = '';
+        if (version_compare(CodeIgniter::CI_VERSION, '4.3.0', '>=')) {
+            CITestStreamFilter::registration();
+            CITestStreamFilter::addOutputFilter();
+            CITestStreamFilter::addErrorFilter();
+        } else {
+            CITestStreamFilter::$buffer = '';
 
-        $this->streamFilter = stream_filter_append(STDOUT, 'CITestStreamFilter');
-        $this->streamFilter = stream_filter_append(STDERR, 'CITestStreamFilter');
+            $this->streamFilter = stream_filter_append(STDOUT, 'CITestStreamFilter');
+            $this->streamFilter = stream_filter_append(STDERR, 'CITestStreamFilter');
+        }
 
         if (is_file(HOMEPATH . 'src/Models/UserModel.php')) {
             copy(HOMEPATH . 'src/Models/UserModel.php', HOMEPATH . 'src/Models/UserModel.php.bak');
@@ -34,7 +41,13 @@ protected function tearDown(): void
     {
         parent::tearDown();
 
-        stream_filter_remove($this->streamFilter);
+        if (version_compare(CodeIgniter::CI_VERSION, '4.3.0', '>=')) {
+            CITestStreamFilter::removeOutputFilter();
+            CITestStreamFilter::removeErrorFilter();
+        } else {
+            stream_filter_remove($this->streamFilter);
+        }
+
         $this->deleteTestFiles();
 
         if (is_file(HOMEPATH . 'src/Models/UserModel.php.bak')) {