diff --git a/stubs/core.stub b/stubs/core.stub
index 9a4d8a711c..beee073b9d 100644
--- a/stubs/core.stub
+++ b/stubs/core.stub
@@ -461,3 +461,8 @@ function proc_open($command, array $descriptor_spec, &$pipes, ?string $cwd = nul
  * @param-out list<int>    $weights
  */
 function getmxrr(string $hostname, &$hosts, &$weights = null): bool {}
+
+/**
+ * @return ($path is non-empty-string ? non-empty-string : string)
+ */
+function dirname(string $path, int $levels = 1): string {}
diff --git a/tests/PHPStan/Rules/Constants/data/value-assigned-to-define.php b/tests/PHPStan/Rules/Constants/data/value-assigned-to-define.php
index 1bd09e86c6..2503a62748 100644
--- a/tests/PHPStan/Rules/Constants/data/value-assigned-to-define.php
+++ b/tests/PHPStan/Rules/Constants/data/value-assigned-to-define.php
@@ -12,5 +12,6 @@
 define('A_NON_EMPTY_STRING', '');
 define('A_NON_EMPTY_STRING', '0');
 define('A_NON_EMPTY_STRING', getString());
+define('A_NON_EMPTY_STRING', dirname(__DIR__, 2));
 
 function getString(): string {}