diff --git a/sys/lib/Makefile b/sys/hash_string/Makefile
similarity index 100%
rename from sys/lib/Makefile
rename to sys/hash_string/Makefile
diff --git a/sys/lib/hash_string.c b/sys/hash_string/hash_string.c
similarity index 87%
rename from sys/lib/hash_string.c
rename to sys/hash_string/hash_string.c
index 2104f7049d..a23d194e55 100644
--- a/sys/lib/hash_string.c
+++ b/sys/hash_string/hash_string.c
@@ -1,13 +1,17 @@
-/**
- * Hash string implementation
- *
+/*
  * Copyright (C) 2013 Kaspar Schleiser <kaspar@schleiser.de>
  *
  * This file is subject to the terms and conditions of the GNU Lesser
  * General Public License v2.1. See the file LICENSE in the top level
  * directory for more details.
+ */
+
+/**
+ * @defgroup sys_hash_string
+ * @ingroup sys
+ *
+ * @brief Hash string implementation
  *
- * @ingroup sys_lib
  * @{
  * @file
  * @author Kaspar Schleiser <kaspar@schleiser.de>