diff --git a/stubs/core.stub b/stubs/core.stub
index f2b72c235b..de4c904423 100644
--- a/stubs/core.stub
+++ b/stubs/core.stub
@@ -318,3 +318,12 @@ function abs($num) {}
  * @return ($categorize is true ? array<string, array<string, mixed>> : array<string, mixed>)
  */
 function get_defined_constants(bool $categorize = false): array {}
+
+/**
+ * @param array<string> $long_options
+ * @param mixed $rest_index
+ * @param-out positive-int $rest_index
+ * @return __benevolent<array<string,string>|array<string,false>|array<string,list<mixed>>|false>
+ */
+function getopt(string $short_options, array $long_options = [], &$rest_index = null) {}
+
diff --git a/tests/PHPStan/Analyser/nsrt/getopt.php b/tests/PHPStan/Analyser/nsrt/getopt.php
index 453667cd51..aae0e128e5 100644
--- a/tests/PHPStan/Analyser/nsrt/getopt.php
+++ b/tests/PHPStan/Analyser/nsrt/getopt.php
@@ -5,5 +5,6 @@
 use function getopt;
 use function PHPStan\Testing\assertType;
 
-$opts = getopt("ab:c::", ["longopt1", "longopt2:", "longopt3::"]);
+$opts = getopt("ab:c::", ["longopt1", "longopt2:", "longopt3::"], $restIndex);
 assertType('(array<string, list<mixed>|string|false>|false)', $opts);
+assertType('int<1, max>', $restIndex);