diff --git a/include/polarssl/ecp.h b/include/polarssl/ecp.h
index 9b83bc51b..6dec5bd9c 100644
--- a/include/polarssl/ecp.h
+++ b/include/polarssl/ecp.h
@@ -413,6 +413,8 @@ int ecp_point_read_binary( const ecp_group *grp, ecp_point *P,
  * \param buf       $(Start of input buffer)
  * \param len       Buffer length
  *
+ * \note            buf is updated to point right after the ECPoint on exit
+ *
  * \return          O if successful,
  *                  POLARSSL_ERR_MPI_XXX if initialization failed
  *                  POLARSSL_ERR_ECP_BAD_INPUT_DATA if input is invalid
@@ -479,6 +481,8 @@ int ecp_use_known_dp( ecp_group *grp, ecp_group_id index );
  * \param buf       &(Start of input buffer)
  * \param len       Buffer length
  *
+ * \note            buf is updated to point right after ECParameters on exit
+ *
  * \return          O if successful,
  *                  POLARSSL_ERR_MPI_XXX if initialization failed
  *                  POLARSSL_ERR_ECP_BAD_INPUT_DATA if input is invalid