diff --git a/crates/kitsune-db/tests/unicode_collation.rs b/crates/kitsune-db/tests/unicode_collation.rs
index de02c6d78..08aac0ffc 100644
--- a/crates/kitsune-db/tests/unicode_collation.rs
+++ b/crates/kitsune-db/tests/unicode_collation.rs
@@ -3,7 +3,7 @@ use diesel_async::{scoped_futures::ScopedFutureExt, AsyncPgConnection, RunQueryD
 use kitsune_db::{
     model::{
         account::{Account, ActorType, NewAccount},
-        user::User,
+        user::{NewUser, User},
     },
     schema::{accounts, users},
 };
@@ -41,6 +41,27 @@ async fn create_account(conn: &mut AsyncPgConnection, username: &str) -> Result<
         .map_err(Into::into)
 }
 
+async fn create_user(conn: &mut AsyncPgConnection, username: &str) -> Result<User> {
+    let account = create_account(conn, Uuid::now_v7().to_string().as_str()).await?;
+
+    diesel::insert_into(users::table)
+        .values(NewUser {
+            id: Uuid::now_v7(),
+            account_id: account.id,
+            oidc_id: None,
+            username,
+            email: format!("{username}@kitsune.example").as_str(),
+            password: None,
+            domain: "kitsune.example",
+            private_key: "---WHATEVER---",
+            confirmation_token: Uuid::now_v7().to_string().as_str(),
+        })
+        .returning(User::as_returning())
+        .get_result(conn)
+        .await
+        .map_err(Into::into)
+}
+
 #[tokio::test]
 #[serial_test::serial]
 async fn accounts_username() {
@@ -76,5 +97,31 @@ async fn accounts_username() {
 #[tokio::test]
 #[serial_test::serial]
 async fn users_username() {
-    database_test(|db_pool| async move {}).await;
+    database_test(|db_pool| async move {
+        db_pool
+            .with_connection(|conn| {
+                async move {
+                    let initial_insert = create_user(conn, "aumetra").await;
+                    assert!(initial_insert.is_ok());
+
+                    let case_mutation = create_user(conn, "AuMeTrA").await;
+                    assert!(case_mutation.is_err());
+
+                    let unicode_mutation_1 = create_user(conn, "äumeträ").await;
+                    assert!(unicode_mutation_1.is_err());
+
+                    let unicode_mutation_2 = create_user(conn, "🅰umetr🅰").await;
+                    assert!(unicode_mutation_2.is_err());
+
+                    let unicode_case_mutation = create_user(conn, "🅰UMETR🅰").await;
+                    assert!(unicode_case_mutation.is_err());
+
+                    Result::Ok(())
+                }
+                .scoped()
+            })
+            .await
+            .unwrap();
+    })
+    .await;
 }