diff --git a/src/Core/Logger/Util/FileSystem.php b/src/Core/Logger/Util/FileSystem.php
index 2d05faf50d..b1c402946a 100644
--- a/src/Core/Logger/Util/FileSystem.php
+++ b/src/Core/Logger/Util/FileSystem.php
@@ -12,7 +12,7 @@ use Friendica\Core\Logger\Exception\LoggerUnusableException;
 /**
  * Util class for filesystem manipulation for Logger classes
  */
-class FileSystem
+class FileSystem implements FileSystemUtil
 {
 	/**
 	 * @var string a error message
diff --git a/src/Core/Logger/Util/FileSystemUtil.php b/src/Core/Logger/Util/FileSystemUtil.php
new file mode 100644
index 0000000000..f4052b8c59
--- /dev/null
+++ b/src/Core/Logger/Util/FileSystemUtil.php
@@ -0,0 +1,38 @@
+<?php
+
+// Copyright (C) 2010-2024, the Friendica project
+// SPDX-FileCopyrightText: 2010-2024 the Friendica project
+//
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
+namespace Friendica\Core\Logger\Util;
+
+use Friendica\Core\Logger\Exception\LoggerUnusableException;
+
+/**
+ * interface for Util class for filesystem manipulation for Logger classes
+ */
+interface FileSystemUtil
+{
+	/**
+	 * Creates a directory based on a file, which gets accessed
+	 *
+	 * @param string $file The file
+	 *
+	 * @return string The directory name (empty if no directory is found, like urls)
+	 *
+	 * @throws LoggerUnusableException
+	 */
+	public function createDir(string $file): string;
+
+	/**
+	 * Creates a stream based on a URL (could be a local file or a real URL)
+	 *
+	 * @param string $url The file/url
+	 *
+	 * @return resource the open stream resource
+	 *
+	 * @throws LoggerUnusableException
+	 */
+	public function createStream(string $url);
+}