diff --git a/sys/include/hashes/sha256.h b/sys/include/hashes/sha256.h
index 0682c7e57b365d46c494901d2489c0f9508b4174..5025f5455ff8870db345b9716b2a65edf6e78cc2 100644
--- a/sys/include/hashes/sha256.h
+++ b/sys/include/hashes/sha256.h
@@ -31,7 +31,9 @@
 
 
 /**
+ * @defgroup    sys_hashes_sha256 SHA-256
  * @ingroup     sys_hashes
+ * @brief       Implementation of the SHA-256 hashing function
  * @{
  *
  * @file