diff --git a/schemes/users.py b/schemes/users.py
index 4ccbfb63..cc08f3d5 100644
--- a/schemes/users.py
+++ b/schemes/users.py
@@ -69,8 +69,8 @@ def get_all(self) -> List[User]:
 @api_key_auth
 @inject.autoparams()
 def add(users: UserRepository) -> Response:
-    json = request.get_json()
-    users.add(*[User(element["email"]) for element in json])
+    users_repr = [UserRepr(**element) for element in request.get_json()]
+    users.add(*[user_repr.to_domain() for user_repr in users_repr])
     return Response(status=201)
 
 
@@ -80,3 +80,11 @@ def add(users: UserRepository) -> Response:
 def clear(users: UserRepository) -> Response:
     users.clear()
     return Response(status=204)
+
+
+@dataclass
+class UserRepr:
+    email: str
+
+    def to_domain(self) -> User:
+        return User(email=self.email)
diff --git a/tests/e2e/app_client.py b/tests/e2e/app_client.py
index 4687e4f5..e31cdc59 100644
--- a/tests/e2e/app_client.py
+++ b/tests/e2e/app_client.py
@@ -1,3 +1,7 @@
+from __future__ import annotations
+
+from dataclasses import dataclass
+
 import requests
 
 
@@ -8,12 +12,11 @@ def __init__(self, url: str, api_key: str):
         self._url = url
         self._api_key = api_key
 
-    def add_user(self, email: str) -> None:
-        users = [{"email": email}]
+    def add_user(self, user: UserRepr) -> None:
         response = requests.post(
             f"{self._url}/users",
             headers={"Authorization": f"API-Key {self._api_key}"},
-            json=users,
+            json=[user.__dict__],
             timeout=self.DEFAULT_TIMEOUT,
         )
         assert response.status_code == 201
@@ -23,3 +26,8 @@ def clear_users(self) -> None:
             f"{self._url}/users", headers={"Authorization": f"API-Key {self._api_key}"}, timeout=self.DEFAULT_TIMEOUT
         )
         assert response.status_code == 204
+
+
+@dataclass
+class UserRepr:
+    email: str
diff --git a/tests/e2e/test_schemes.py b/tests/e2e/test_schemes.py
index 8874e68f..b306f139 100644
--- a/tests/e2e/test_schemes.py
+++ b/tests/e2e/test_schemes.py
@@ -2,7 +2,7 @@
 from flask import Flask
 from playwright.sync_api import Page
 
-from tests.e2e.app_client import AppClient
+from tests.e2e.app_client import AppClient, UserRepr
 from tests.e2e.oidc_server.users import StubUser
 from tests.e2e.oidc_server.web_client import OidcClient
 from tests.e2e.pages import SchemesPage
@@ -15,7 +15,7 @@ def oidc_user(self, oidc_client: OidcClient) -> None:
         oidc_client.add_user(StubUser("boardman", "boardman@example.com"))
 
     def test_schemes_when_authorized(self, app_client: AppClient, app: Flask, page: Page) -> None:
-        app_client.add_user("boardman@example.com")
+        app_client.add_user(UserRepr(email="boardman@example.com"))
 
         schemes_page = SchemesPage(app, page).open()
 
@@ -27,7 +27,7 @@ def test_schemes_when_unauthorized(self, app: Flask, page: Page) -> None:
         assert unauthorized_page.visible()
 
     def test_header_sign_out(self, app_client: AppClient, app: Flask, page: Page) -> None:
-        app_client.add_user("boardman@example.com")
+        app_client.add_user(UserRepr(email="boardman@example.com"))
         schemes_page = SchemesPage(app, page).open()
 
         start_page = schemes_page.header.sign_out()
diff --git a/tests/e2e/test_start.py b/tests/e2e/test_start.py
index 778bfc10..265fb219 100644
--- a/tests/e2e/test_start.py
+++ b/tests/e2e/test_start.py
@@ -2,7 +2,7 @@
 from flask import Flask
 from playwright.sync_api import Page
 
-from tests.e2e.app_client import AppClient
+from tests.e2e.app_client import AppClient, UserRepr
 from tests.e2e.oidc_server.users import StubUser
 from tests.e2e.oidc_server.web_client import OidcClient
 from tests.e2e.pages import StartPage
@@ -28,7 +28,7 @@ def test_start_shows_login(self, app: Flask, page: Page) -> None:
 class TestAuthenticated:
     def test_start_shows_schemes(self, oidc_client: OidcClient, app_client: AppClient, app: Flask, page: Page) -> None:
         oidc_client.add_user(StubUser("boardman", "boardman@example.com"))
-        app_client.add_user("boardman@example.com")
+        app_client.add_user(UserRepr(email="boardman@example.com"))
         start_page = StartPage(app, page).open()
         start_page.start()