diff --git a/src/db.rs b/src/db.rs
index 43bb7df59..28c9cd32f 100644
--- a/src/db.rs
+++ b/src/db.rs
@@ -11,6 +11,7 @@ pub mod issue_data;
 pub mod jobs;
 pub mod notifications;
 pub mod rustc_commits;
+pub mod users;
 
 const CERT_URL: &str = "https://truststore.pki.rds.amazonaws.com/global/global-bundle.pem";
 
diff --git a/src/db/notifications.rs b/src/db/notifications.rs
index 1e9f295ac..3077ef13a 100644
--- a/src/db/notifications.rs
+++ b/src/db/notifications.rs
@@ -15,17 +15,6 @@ pub struct Notification {
     pub team_name: Option<String>,
 }
 
-/// Add a new user (if not existing)
-pub async fn record_username(db: &DbClient, user_id: u64, username: &str) -> anyhow::Result<()> {
-    db.execute(
-        "INSERT INTO users (user_id, username) VALUES ($1, $2) ON CONFLICT DO NOTHING",
-        &[&(user_id as i64), &username],
-    )
-    .await
-    .context("inserting user id / username")?;
-    Ok(())
-}
-
 pub async fn record_ping(db: &DbClient, notification: &Notification) -> anyhow::Result<()> {
     db.execute("INSERT INTO notifications (user_id, origin_url, origin_html, time, short_description, team_name, idx)
         VALUES (
diff --git a/src/db/users.rs b/src/db/users.rs
new file mode 100644
index 000000000..ae8d6efe2
--- /dev/null
+++ b/src/db/users.rs
@@ -0,0 +1,60 @@
+use crate::github::User;
+use anyhow::Context;
+use tokio_postgres::Client as DbClient;
+
+/// Add a new user.
+/// If an user already exists, updates their username.
+pub async fn record_username(db: &DbClient, user_id: u64, username: &str) -> anyhow::Result<()> {
+    db.execute(
+        r"
+INSERT INTO users (user_id, username) VALUES ($1, $2)
+ON CONFLICT (user_id)
+DO UPDATE SET username = $2",
+        &[&(user_id as i64), &username],
+    )
+    .await
+    .context("inserting user id / username")?;
+    Ok(())
+}
+
+/// Return a user from the DB.
+pub async fn get_user(db: &DbClient, user_id: u64) -> anyhow::Result<Option<User>> {
+    let row = db
+        .query_opt(
+            r"
+SELECT username
+FROM users
+WHERE user_id = $1;",
+            &[&(user_id as i64)],
+        )
+        .await
+        .context("cannot load user from DB")?;
+    Ok(row.map(|row| {
+        let username: &str = row.get(0);
+        User {
+            id: user_id,
+            login: username.to_string(),
+        }
+    }))
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::db::users::{get_user, record_username};
+    use crate::tests::run_test;
+
+    #[tokio::test]
+    async fn update_username_on_conflict() {
+        run_test(|ctx| async {
+            let db = ctx.db_client().await;
+
+            record_username(&db, 1, "Foo").await?;
+            record_username(&db, 1, "Bar").await?;
+
+            assert_eq!(get_user(&db, 1).await?.unwrap().login, "Bar");
+
+            Ok(ctx)
+        })
+        .await;
+    }
+}
diff --git a/src/handlers/notification.rs b/src/handlers/notification.rs
index 87fe20539..e33eb9568 100644
--- a/src/handlers/notification.rs
+++ b/src/handlers/notification.rs
@@ -4,7 +4,7 @@
 //!
 //! Parsing is done in the `parser::command::ping` module.
 
-use crate::db::notifications;
+use crate::db::{notifications, users};
 use crate::github::get_id_for_username;
 use crate::{
     github::{self, Event},
@@ -92,7 +92,7 @@ pub async fn handle(ctx: &Context, event: &Event) -> anyhow::Result<()> {
                 continue;
             }
 
-            if let Err(err) = notifications::record_username(&client, user.id, &user.login)
+            if let Err(err) = users::record_username(&client, user.id, &user.login)
                 .await
                 .context("failed to record username")
             {
diff --git a/src/handlers/pr_tracking.rs b/src/handlers/pr_tracking.rs
index fb1c9bd0c..f793fb128 100644
--- a/src/handlers/pr_tracking.rs
+++ b/src/handlers/pr_tracking.rs
@@ -7,10 +7,10 @@
 //! - Removes the PR from the workqueue of one team member (after the PR has been unassigned or closed)
 
 use super::assign::{FindReviewerError, REVIEWER_HAS_NO_CAPACITY, SELF_ASSIGN_HAS_NO_CAPACITY};
+use crate::db::users::record_username;
 use crate::github::User;
 use crate::{
     config::ReviewPrefsConfig,
-    db::notifications::record_username,
     github::{IssuesAction, IssuesEvent},
     handlers::Context,
     ReviewPrefs,
diff --git a/src/handlers/pull_requests_assignment_update.rs b/src/handlers/pull_requests_assignment_update.rs
index fe544afeb..c5e6acef9 100644
--- a/src/handlers/pull_requests_assignment_update.rs
+++ b/src/handlers/pull_requests_assignment_update.rs
@@ -1,6 +1,6 @@
 use std::collections::HashMap;
 
-use crate::db::notifications::record_username;
+use crate::db::users::record_username;
 use crate::github::retrieve_pull_requests;
 use crate::jobs::Job;
 use crate::ReviewPrefs;
diff --git a/src/tests/mod.rs b/src/tests/mod.rs
index adfb7c3fa..e24a21251 100644
--- a/src/tests/mod.rs
+++ b/src/tests/mod.rs
@@ -1,5 +1,5 @@
 use crate::db;
-use crate::db::notifications::record_username;
+use crate::db::users::record_username;
 use crate::db::{make_client, ClientPool, PooledClient};
 use crate::github::GithubClient;
 use crate::handlers::Context;