diff --git a/src/Handler/Exam/Users.hs b/src/Handler/Exam/Users.hs
index f93cbc4e9..1912abbd0 100644
--- a/src/Handler/Exam/Users.hs
+++ b/src/Handler/Exam/Users.hs
@@ -973,7 +973,7 @@ postEUsersR tid ssh csh examn = do
 
               guessUser' :: ExamUserTableCsv -> DB (Bool, UserId)
               guessUser' ExamUserTableCsv{..} = do
-                let criteria = PredDNF $ Set.singleton $ impureNonNull $ Set.fromList $ (PLVariable <$>) $ catMaybes $
+                let criteria = PredDNF $ Set.singleton $ impureNonNull $ Set.fromList $ (PLVariable <$>) $ catMaybes
                       [ GuessUserMatrikelnummer <$> csvEUserMatriculation
                       , GuessUserDisplayName <$> csvEUserName
                       , GuessUserSurname <$> csvEUserSurname
diff --git a/src/Handler/ExternalExam/Correct.hs b/src/Handler/ExternalExam/Correct.hs
index 4febbc936..d91dd4590 100644
--- a/src/Handler/ExternalExam/Correct.hs
+++ b/src/Handler/ExternalExam/Correct.hs
@@ -81,7 +81,7 @@ postEECorrectR tid ssh coursen examn = do
               , GuessUserSurname        (ident :: UserSurname)
               , GuessUserFirstName      (ident :: UserFirstName)
               ]
-        in  (maybe [] (either NonEmpty.toList pure)) <$> lift (guessUser pdnf $ Just $ maxCountUserMatches+1)
+        in  maybe [] (either NonEmpty.toList pure) <$> lift (guessUser pdnf $ Just $ maxCountUserMatches+1)
 
     if
       | is _Nothing ciqResults, is _Nothing ciqGrade -> do
diff --git a/src/Handler/Utils/Users.hs b/src/Handler/Utils/Users.hs
index a0fac546d..7d95a2e15 100644
--- a/src/Handler/Utils/Users.hs
+++ b/src/Handler/Utils/Users.hs
@@ -156,7 +156,7 @@ guessUser (((Set.toList . toNullable) <$>) . Set.toList . dnfTerms -> criteria)
         convertLdapResults xs  = Just $ Left $ NonEmpty.fromList xs
       
       if
-        | x : [] <- users'
+        | [x] <- users'
         , Just True == matchesMatriculation x || didLdap
           -> return $ Just $ Right x
         | x : x' : _ <- users'