diff --git a/src/Runner/StandardTestSuiteLoader.php b/src/Runner/StandardTestSuiteLoader.php
index 929c0c0153b..3752d4c137f 100644
--- a/src/Runner/StandardTestSuiteLoader.php
+++ b/src/Runner/StandardTestSuiteLoader.php
@@ -52,19 +52,12 @@ public function load(string $suiteClassFile): ReflectionClass
         }
 
         if (!class_exists($suiteClassName, false)) {
-            // Perhaps this file defines a class inside a namespace? Let's check...
             $offset = 0 - strlen($suiteClassName);
 
             foreach ($loadedClasses as $loadedClass) {
-                // Detect modern namespace (eg './tests/Foo/Bar/WhizBangTest.php' <=> 'Foo\Bar\WhizBangTest')
-                if (stripos(substr($loadedClass, $offset - 1), '\\' . $suiteClassName) === 0) {
-                    $suiteClassName = $loadedClass;
-
-                    break;
-                }
-
-                // Detect old-school namespace (eg 'tests/Foo/Bar/WhizBangTest.php' <=> 'Foo_Bar_WhizBangTest'; #5020)
-                if (stripos(substr($loadedClass, $offset - 1), '_' . $suiteClassName) === 0) {
+                // @see https://github.com/sebastianbergmann/phpunit/issues/5020
+                if (stripos(substr($loadedClass, $offset - 1), '\\' . $suiteClassName) === 0 ||
+                    stripos(substr($loadedClass, $offset - 1), '_' . $suiteClassName) === 0) {
                     $suiteClassName = $loadedClass;
 
                     break;