diff --git a/sys/include/hashes/md5.h b/sys/include/hashes/md5.h
index ccb38a6568..56623ad743 100644
--- a/sys/include/hashes/md5.h
+++ b/sys/include/hashes/md5.h
@@ -19,7 +19,7 @@
 
 /**
  * @defgroup    sys_hashes_md5 MD5
- * @ingroup     sys_hashes
+ * @ingroup     sys_hashes_unkeyed
  * @brief       Implementation of the MD5 hashing function
  *
  *  None of this will make any sense unless you're studying RFC 1321 as you