diff --git a/typo3/sysext/saltedpasswords/Classes/Salt/AbstractComposedSalt.php b/typo3/sysext/saltedpasswords/Classes/Salt/AbstractComposedSalt.php
index 3d1829f78c82c6824d787ea1b979216a96e500f0..69f829f9956dbc041fb0b742b20903d5c0a69a61 100644
--- a/typo3/sysext/saltedpasswords/Classes/Salt/AbstractComposedSalt.php
+++ b/typo3/sysext/saltedpasswords/Classes/Salt/AbstractComposedSalt.php
@@ -19,7 +19,7 @@ namespace TYPO3\CMS\Saltedpasswords\Salt;
  * Abstract class with methods needed to be extended
  * in a salted hashing class that composes an own salted password hash.
  */
-abstract class AbstractComposedSalt implements SaltInterface
+abstract class AbstractComposedSalt implements ComposedSaltInterface
 {
     /**
      * Method applies settings (prefix, optional hash count, optional suffix)
diff --git a/typo3/sysext/saltedpasswords/Classes/Salt/ComposedSaltInterface.php b/typo3/sysext/saltedpasswords/Classes/Salt/ComposedSaltInterface.php
new file mode 100644
index 0000000000000000000000000000000000000000..467c64cbc4965a5a4d53e9e90b7a6d1791bbe228
--- /dev/null
+++ b/typo3/sysext/saltedpasswords/Classes/Salt/ComposedSaltInterface.php
@@ -0,0 +1,38 @@
+<?php
+declare(strict_types=1);
+namespace TYPO3\CMS\Saltedpasswords\Salt;
+
+/*
+ * This file is part of the TYPO3 CMS project.
+ *
+ * It is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU General Public License, either version 2
+ * of the License, or any later version.
+ *
+ * For the full copyright and license information, please read the
+ * LICENSE.txt file that was distributed with this source code.
+ *
+ * The TYPO3 project - inspiring people to share!
+ */
+
+/**
+ * Interface for implementing salts that compose the password-hash string
+ * themselves.
+ */
+interface ComposedSaltInterface extends SaltInterface
+{
+    /**
+     * Returns length of required salt.
+     *
+     * @return int Length of required salt
+     */
+    public function getSaltLength(): int;
+
+    /**
+     * Method determines if a given string is a valid salt
+     *
+     * @param string $salt String to check
+     * @return bool TRUE if it's valid salt, otherwise FALSE
+     */
+    public function isValidSalt(string $salt): bool;
+}