diff --git a/src/Mbstring/bootstrap80.php b/src/Mbstring/bootstrap80.php
index 8016bdb48..5be7d2018 100644
--- a/src/Mbstring/bootstrap80.php
+++ b/src/Mbstring/bootstrap80.php
@@ -93,7 +93,7 @@ function mb_strrpos(?string $haystack, ?string $needle, ?int $offset = 0, ?strin
     function mb_strstr(?string $haystack, ?string $needle, ?bool $before_needle = false, ?string $encoding = null): string|false { return p\Mbstring::mb_strstr((string) $haystack, (string) $needle, (bool) $before_needle, $encoding); }
 }
 if (!function_exists('mb_get_info')) {
-    function mb_get_info(?string $type = 'all'): array|string|int|false { return p\Mbstring::mb_get_info((string) $type); }
+    function mb_get_info(?string $type = 'all'): array|string|int|false|null { return p\Mbstring::mb_get_info((string) $type); }
 }
 if (!function_exists('mb_http_output')) {
     function mb_http_output(?string $encoding = null): string|bool { return p\Mbstring::mb_http_output($encoding); }
diff --git a/src/Util/TestListenerTrait.php b/src/Util/TestListenerTrait.php
index 3b87d426d..37e2ee4cb 100644
--- a/src/Util/TestListenerTrait.php
+++ b/src/Util/TestListenerTrait.php
@@ -129,6 +129,13 @@ function {$f['name']}{$f['signature']}
                         'array|string|null $string' => 'array|string $string',
                         'array|string|null $from_encoding = null' => 'array|string|null $from_encoding = null',
                         'array|string|null $from_encoding' => 'array|string $from_encoding',
+                        'string $characters = null' => '?string $characters = null',
+                        'string $charset = null' => '?string $charset = null',
+                        'string $encoding = null' => '?string $encoding = null',
+                        'string $language = null' => '?string $language = null',
+                        'string $transfer_encoding = null' => '?string $transfer_encoding = null',
+                        'string $type = null' => '?string $type = null',
+                        'int $length = null' => '?int $length = null',
                     ];
 
                     if (strtr($polyfillSignature, $map) !== $originalSignature) {