diff --git a/phpstan-baseline.php b/phpstan-baseline.php
index c49b156548eb..2fd4d79af642 100644
--- a/phpstan-baseline.php
+++ b/phpstan-baseline.php
@@ -12955,24 +12955,6 @@
 	'count' => 1,
 	'path' => __DIR__ . '/tests/system/ControllerTest.php',
 ];
-$ignoreErrors[] = [
-	// identifier: missingType.property
-	'message' => '#^Property class@anonymous/tests/system/ControllerTest\\.php\\:128\\:\\:\\$signup has no type specified\\.$#',
-	'count' => 1,
-	'path' => __DIR__ . '/tests/system/ControllerTest.php',
-];
-$ignoreErrors[] = [
-	// identifier: missingType.property
-	'message' => '#^Property class@anonymous/tests/system/ControllerTest\\.php\\:128\\:\\:\\$signup_errors has no type specified\\.$#',
-	'count' => 1,
-	'path' => __DIR__ . '/tests/system/ControllerTest.php',
-];
-$ignoreErrors[] = [
-	// identifier: missingType.property
-	'message' => '#^Property class@anonymous/tests/system/ControllerTest\\.php\\:151\\:\\:\\$signup has no type specified\\.$#',
-	'count' => 1,
-	'path' => __DIR__ . '/tests/system/ControllerTest.php',
-];
 $ignoreErrors[] = [
 	// identifier: argument.type
 	'message' => '#^Parameter \\#1 \\$cookies of class CodeIgniter\\\\Cookie\\\\CookieStore constructor expects array\\<CodeIgniter\\\\Cookie\\\\Cookie\\>, array\\<int, DateTimeImmutable\\> given\\.$#',
diff --git a/tests/system/ControllerTest.php b/tests/system/ControllerTest.php
index 7cbe664aabc0..add07fc20dd4 100644
--- a/tests/system/ControllerTest.php
+++ b/tests/system/ControllerTest.php
@@ -126,10 +126,17 @@ public function testValidateWithStringRulesNotFound(): void
     public function testValidateWithStringRulesFoundReadMessagesFromValidationConfig(): void
     {
         $validation = new class () extends ValidationConfig {
-            public $signup = [
+            /**
+             * @var array<string, string>
+             */
+            public array $signup = [
                 'username' => 'required',
             ];
-            public $signup_errors = [
+
+            /**
+             * @var array<string, array<string, string>>
+             */
+            public array $signup_errors = [
                 'username' => [
                     'required' => 'You must choose a username.',
                 ],
@@ -149,7 +156,10 @@ public function testValidateWithStringRulesFoundReadMessagesFromValidationConfig
     public function testValidateWithStringRulesFoundUseMessagesParameter(): void
     {
         $validation = new class () extends ValidationConfig {
-            public $signup = [
+            /**
+             * @var array<string, string>
+             */
+            public array $signup = [
                 'username' => 'required',
             ];
         };
@@ -191,6 +201,77 @@ public function testValidateData(): void
         );
     }
 
+    public function testValidateDataWithCustomErrorMessage(): void
+    {
+        // make sure we can instantiate one
+        $this->controller = new Controller();
+        $this->controller->initController($this->request, $this->response, $this->logger);
+
+        $method = $this->getPrivateMethodInvoker($this->controller, 'validateData');
+
+        $data = [
+            'username' => 'a',
+            'password' => '123',
+        ];
+        $rules = [
+            'username' => 'required|min_length[3]',
+            'password' => 'required|min_length[10]',
+        ];
+        $errors = [
+            'username' => [
+                'required'   => 'Please fill "{field}".',
+                'min_length' => '"{field}" must be {param} letters or longer.',
+            ],
+        ];
+        $this->assertFalse($method($data, $rules, $errors));
+        $this->assertSame(
+            '"username" must be 3 letters or longer.',
+            Services::validation()->getError('username')
+        );
+        $this->assertSame(
+            'The password field must be at least 10 characters in length.',
+            Services::validation()->getError('password')
+        );
+    }
+
+    public function testValidateDataWithCustomErrorMessageLabeledStyle(): void
+    {
+        // make sure we can instantiate one
+        $this->controller = new Controller();
+        $this->controller->initController($this->request, $this->response, $this->logger);
+
+        $method = $this->getPrivateMethodInvoker($this->controller, 'validateData');
+
+        $data = [
+            'username' => 'a',
+            'password' => '123',
+        ];
+        $rules = [
+            'username' => [
+                'label'  => 'Username',
+                'rules'  => 'required|min_length[3]',
+                'errors' => [
+                    'required'   => 'Please fill "{field}".',
+                    'min_length' => '"{field}" must be {param} letters or longer.',
+                ],
+            ],
+            'password' => [
+                'required|min_length[10]',
+                'label' => 'Password',
+                'rules' => 'required|min_length[10]',
+            ],
+        ];
+        $this->assertFalse($method($data, $rules));
+        $this->assertSame(
+            '"Username" must be 3 letters or longer.',
+            Services::validation()->getError('username')
+        );
+        $this->assertSame(
+            'The Password field must be at least 10 characters in length.',
+            Services::validation()->getError('password')
+        );
+    }
+
     public function testHelpers(): void
     {
         $this->controller = new class () extends Controller {