diff --git a/app/UniWorX.hs b/app/UniWorX.hs
index e0a5f93..f373ef5 100644
--- a/app/UniWorX.hs
+++ b/app/UniWorX.hs
@@ -10,7 +10,6 @@
              TemplateHaskell,
              TypeFamilies,
              TypeApplications,
-             DeriveGeneric,
              DerivingStrategies,
              StandaloneDeriving,
              UndecidableInstances,
@@ -34,7 +33,7 @@ import Conduit (ResourceT)
 import Data.Map (Map(..))
 import Data.String (IsString(..))
 import Data.Text (Text(..))
-import Data.Yaml (decodeFileThrow, FromJSON(..), Value(..), (.:))
+import Data.Yaml (decodeFileThrow, FromJSON(..), Value(..), (.:), (.:?))
 import qualified Data.Map as M
 import qualified Data.Text as T
 
@@ -42,8 +41,6 @@ import Database.Persist
 import Database.Persist.TH
 import Database.Persist.Postgresql
 
-import GHC.Generics
-
 import System.Environment (lookupEnv)
 
 
@@ -61,14 +58,28 @@ share [mkPersist sqlSettings, mkMigrate "migrateAll"] [persistLowerCase|
     compPersNumber  Text Maybe
     compDepartment  Text Maybe
     postAddress     Text Maybe
-    deriving Eq Show Generic
+    deriving Eq Show
 |]
 
-instance FromJSON User
+instance FromJSON User where
+  parseJSON (Object o) = User
+    <$> o .:  "userFirstName"
+    <*> o .:  "userSurname"
+    <*> o .:  "userEmail"
+    <*> o .:? "userMatrikelnummer"
+    <*> o .:? "userTitle"
+    <*> o .:? "userSex"
+    <*> o .:? "userBirthday"
+    <*> o .:? "userTelephone"
+    <*> o .:? "userMobile"
+    <*> o .:? "userCompanyPersonalNumber"
+    <*> o .:? "userCompanyDepartment"
+    <*> o .:? "userPostAddress"
+  parseJSON _ = error "Oauth2 Mock Server: invalid test user format"
 
 data TestUserSpec = TestUsers
-  { specialUsers :: [User]
-  , randomUsers  :: Map Text [Text]
+  { specialUsers :: [Map Text User]
+  , randomUsers  :: Map Text [Maybe Text]
   } deriving (Show)
 
 instance FromJSON TestUserSpec where
@@ -91,7 +102,8 @@ initDB = do
     runMigration migrateAll
     testUsers <- decodeFileThrow @DB @TestUserSpec testUserFile
     liftIO . putStrLn $ "the test users:\n" ++ show testUsers
-    forM_ (specialUsers testUsers) $ void . insert
+    let users = M.elems . mconcat $ specialUsers testUsers
+    forM_ users $ void . insert
 
 
 instance UserData (Entity User) (Map Text Text) where