diff --git a/src/controllers/crate_owner_invitation.rs b/src/controllers/crate_owner_invitation.rs
index 6afae1e3437..079f320fe82 100644
--- a/src/controllers/crate_owner_invitation.rs
+++ b/src/controllers/crate_owner_invitation.rs
@@ -2,9 +2,10 @@ use crate::app::AppState;
 use crate::auth::AuthCheck;
 use crate::auth::Authentication;
 use crate::controllers::helpers::pagination::{Page, PaginationOptions, PaginationQueryParams};
+use crate::models::crate_owner_invitation::AcceptError;
 use crate::models::{Crate, CrateOwnerInvitation, Rights, User};
 use crate::schema::{crate_owner_invitations, crates, users};
-use crate::util::errors::{bad_request, forbidden, internal, AppResult, BoxedAppError};
+use crate::util::errors::{bad_request, custom, forbidden, internal, AppResult, BoxedAppError};
 use crate::util::RequestUtils;
 use crate::views::{
     EncodableCrateOwnerInvitation, EncodableCrateOwnerInvitationV1, EncodablePublicUser,
@@ -20,6 +21,7 @@ use diesel::prelude::*;
 use diesel::sql_types::Bool;
 use diesel_async::{AsyncPgConnection, RunQueryDsl};
 use http::request::Parts;
+use http::StatusCode;
 use indexmap::IndexMap;
 use std::collections::{HashMap, HashSet};
 
@@ -380,3 +382,19 @@ pub async fn accept_crate_owner_invitation_with_token(
         },
     }))
 }
+
+impl From<AcceptError> for BoxedAppError {
+    fn from(error: AcceptError) -> Self {
+        match error {
+            AcceptError::Diesel(error) => error.into(),
+            AcceptError::Expired { crate_name } => {
+                let detail = format!(
+                    "The invitation to become an owner of the {crate_name} crate expired. \
+                    Please reach out to an owner of the crate to request a new invitation.",
+                );
+
+                custom(StatusCode::GONE, detail)
+            }
+        }
+    }
+}
diff --git a/src/models.rs b/src/models.rs
index 03bfc833d0e..5e71967d866 100644
--- a/src/models.rs
+++ b/src/models.rs
@@ -22,7 +22,7 @@ pub mod helpers;
 
 mod action;
 pub mod category;
-mod crate_owner_invitation;
+pub mod crate_owner_invitation;
 pub mod default_versions;
 mod deleted_crate;
 pub mod dependency;
diff --git a/src/models/crate_owner_invitation.rs b/src/models/crate_owner_invitation.rs
index 94c5be77643..9830ec5defb 100644
--- a/src/models/crate_owner_invitation.rs
+++ b/src/models/crate_owner_invitation.rs
@@ -2,13 +2,11 @@ use chrono::{NaiveDateTime, Utc};
 use diesel::prelude::*;
 use diesel_async::scoped_futures::ScopedFutureExt;
 use diesel_async::{AsyncConnection, AsyncPgConnection, RunQueryDsl};
-use http::StatusCode;
 use secrecy::SecretString;
 
 use crate::config;
 use crate::models::{CrateOwner, OwnerKind};
 use crate::schema::{crate_owner_invitations, crate_owners, crates};
-use crate::util::errors::{custom, AppResult};
 
 #[derive(Debug)]
 pub enum NewCrateOwnerInvitationOutcome {
@@ -109,7 +107,7 @@ impl CrateOwnerInvitation {
         self,
         conn: &mut AsyncPgConnection,
         config: &config::Server,
-    ) -> AppResult<()> {
+    ) -> Result<(), AcceptError> {
         use diesel_async::scoped_futures::ScopedFutureExt;
         use diesel_async::{AsyncConnection, RunQueryDsl};
 
@@ -120,12 +118,7 @@ impl CrateOwnerInvitation {
                 .first(conn)
                 .await?;
 
-            let detail = format!(
-                "The invitation to become an owner of the {crate_name} crate expired. \
-                Please reach out to an owner of the crate to request a new invitation.",
-            );
-
-            return Err(custom(StatusCode::GONE, detail));
+            return Err(AcceptError::Expired { crate_name });
         }
 
         conn.transaction(|conn| {
@@ -170,3 +163,11 @@ impl CrateOwnerInvitation {
         self.created_at + config.ownership_invitations_expiration
     }
 }
+
+#[derive(Debug, thiserror::Error)]
+pub enum AcceptError {
+    #[error(transparent)]
+    Diesel(#[from] diesel::result::Error),
+    #[error("The invitation has expired")]
+    Expired { crate_name: String },
+}