diff --git a/sys/include/ubjson.h b/sys/include/ubjson.h
index fad8544fa1..fd60cb9c3c 100644
--- a/sys/include/ubjson.h
+++ b/sys/include/ubjson.h
@@ -17,9 +17,9 @@
  */
 
 /**
- * @defgroup    sys_ubjson Universal Binary JSON
- * @ingroup     sys
- * @brief       A library to read and write UBJSON serialized data.
+ * @defgroup sys_ubjson  Universal Binary JSON library
+ * @ingroup  sys_serialization
+ * @brief    Provides a library to read and write UBJSON serialized data
  * @{
  *
  * @file
diff --git a/sys/ubjson/ubjson-read.c b/sys/ubjson/ubjson-read.c
index 42dfb85dbe..c53d56fb66 100644
--- a/sys/ubjson/ubjson-read.c
+++ b/sys/ubjson/ubjson-read.c
@@ -17,7 +17,7 @@
  */
 
 /**
- * @ingroup     sys
+ * @ingroup     sys_ubjson
  * @{
  * @file
  * @brief       Universal Binary JSON deserializer
diff --git a/sys/ubjson/ubjson-write.c b/sys/ubjson/ubjson-write.c
index 9a05539fa5..4c8af605c9 100644
--- a/sys/ubjson/ubjson-write.c
+++ b/sys/ubjson/ubjson-write.c
@@ -17,7 +17,7 @@
  */
 
 /**
- * @ingroup     sys
+ * @ingroup     sys_ubjson
  * @{
  * @file
  * @brief       Universal Binary JSON deserializer