diff --git a/tests/integration/it_auth_test.py b/tests/integration/it_auth_test.py
index 6497b4f0..9da5c4d2 100644
--- a/tests/integration/it_auth_test.py
+++ b/tests/integration/it_auth_test.py
@@ -12,7 +12,7 @@ def test_incorrect_username(db_session):
     """Do not remove db_session dependency. It is injected
     in order to trigger db migration.
     """
-    assert (login("unknown", "unknown") == "Incorrect username.")
+    assert (login("unknown", "unknown") == "login.failed")
 
 
 def test_incorrect_password(db_session):
@@ -24,7 +24,7 @@ def test_incorrect_password(db_session):
     db_session.add(employee)
     db_session.commit()
     error = login("vgv", "unknown")
-    assert (error == "Incorrect password.")
+    assert (error == "login.failed")
 
 
 def test_login(db_session):
diff --git a/timeless/auth/auth.py b/timeless/auth/auth.py
index c6c20af6..815799a3 100644
--- a/timeless/auth/auth.py
+++ b/timeless/auth/auth.py
@@ -4,17 +4,16 @@
 
 def login(username="", password=""):
     """Login user
-    @todo #59:30min The backend should return only error codes for login procedure,
-     not hardcoded messages. The codes should then be translated into (mapped to)
-     Strings on the UI, so we can easily have internationalization or change
-     error messages without having to rebuild + redeploy the backend.
+    @todo #201:30min Translate login error codes.
+     The codes returned from login errors should then be translated into (
+     mapped to) Strings on the UI, so we can easily have
+     internationalization or change error messages without having to
+     rebuild + redeploy the backend.
     """
     user = Employee.query.filter_by(username=username).first()
     error = None
-    if user is None:
-        error = "Incorrect username."
-    elif not user.validate_password(password):
-        error = "Incorrect password."
+    if user is None or not user.validate_password(password):
+        error = "login.failed"
     if error is None:
         session.clear()
         session["user_id"] = user.id