diff --git a/rwf/src/http/error.rs b/rwf/src/http/error.rs
index 280c7194..7779aa0a 100644
--- a/rwf/src/http/error.rs
+++ b/rwf/src/http/error.rs
@@ -60,9 +60,11 @@ pub enum Error {
     #[error("content too large")]
     ContentTooLarge(Head),
 
+    /// Model used as user doesn't have an integer id column.
     #[error("user model id is not an integer")]
     UserIdNotAnInteger,
 
+    /// Model used as user has null id column.
     #[error("user model is is null")]
     UserIdIsNull,
 }