diff --git a/src/Concerns/Testable.php b/src/Concerns/Testable.php
index 43c84e3c..e192c8fa 100644
--- a/src/Concerns/Testable.php
+++ b/src/Concerns/Testable.php
@@ -361,7 +361,7 @@ trait Testable
 
                 $parameterType = is_string($argumentIndex)
                     ? ($testParameterTypesByName[$argumentIndex] ?? 'mixed')
-                    : ($testParameterTypes[$argumentIndex] ?? 'mixed');
+                    : $testParameterTypes[$argumentIndex];
 
                 if (in_array($parameterType, [Closure::class, 'callable', 'mixed'])) {
                     continue;
diff --git a/tests/Features/DatasetsTests.php b/tests/Features/DatasetsTests.php
index 1ae7437e..b5607106 100644
--- a/tests/Features/DatasetsTests.php
+++ b/tests/Features/DatasetsTests.php
@@ -458,7 +458,6 @@ test('after describe block with named dataset', function (...$args) {
     expect($args)->toBe(['after']);
 })->with('after-describe');
 
-// Named parameters on datasets
 test('named parameters match by parameter name', function (string $email, string $name) {
     expect($name)->toBe('Taylor');
     expect($email)->toBe('taylor@laravel.com');