diff --git a/src/Handler/Exam/Correct.hs b/src/Handler/Exam/Correct.hs
index 772fcef85..fbd89ff81 100644
--- a/src/Handler/Exam/Correct.hs
+++ b/src/Handler/Exam/Correct.hs
@@ -17,6 +17,11 @@ import Handler.Utils.Exam (fetchExam)
 import Utils.Exam
 
 
+-- | Minimum length of a participant identifier. Identifiers that are shorter would result in too many query results and are therefor rejected.
+minNeedleLength :: Int
+minNeedleLength = 3
+
+
 getECorrectR :: TermId -> SchoolId -> CourseShorthand -> ExamName -> Handler Html
 getECorrectR tid ssh csh examn = do
   MsgRenderer mr <- getMsgRenderer
@@ -54,12 +59,12 @@ postECorrectR tid ssh csh examn = do
   CorrectInterfaceRequest{..} <- requireCheckJsonBody
 
   mayEditResults <- hasWriteAccessTo $ CExamR tid ssh csh examn EUsersR
-  
+
   response <- runDB . exceptT (<$ transactionUndo) return $ do
     Entity eId Exam{..} <- lift $ fetchExam tid ssh csh examn
     euid <- traverse decrypt ciqUser
 
-    guardMExceptT (maybe True ((>= 3) . length) $ euid ^? _Left) $ 
+    guardMExceptT (maybe True ((>= minNeedleLength) . length) $ euid ^? _Left) $ 
       CorrectInterfaceResponseFailure Nothing <$> (getMessageRender <*> pure MsgExamCorrectErrorNeedleTooShort)
 
 
diff --git a/src/Handler/ExternalExam/Correct.hs b/src/Handler/ExternalExam/Correct.hs
index 349dd6154..18583e385 100644
--- a/src/Handler/ExternalExam/Correct.hs
+++ b/src/Handler/ExternalExam/Correct.hs
@@ -15,6 +15,10 @@ import Handler.Utils.ExternalExam
 
 import Utils.Exam
 
+-- | Minimum length of a participant identifier. Identifiers that are shorter would result in too many query results and are therefor rejected.
+minNeedleLength :: Int
+minNeedleLength = 3  -- TODO rethink
+
 
 getEECorrectR :: TermId -> SchoolId -> CourseName -> ExamName -> Handler Html
 getEECorrectR tid ssh coursen examn = do
@@ -59,7 +63,7 @@ postEECorrectR tid ssh coursen examn = do
     Entity eeId ExternalExam{..} <- lift $ fetchExternalExam tid ssh coursen examn
     euid <- traverse decrypt ciqUser
 
-    guardMExceptT (maybe True ((>= 3) . length) $ euid ^? _Left) $  -- TODO rethink max needle length
+    guardMExceptT (maybe True ((>= minNeedleLength) . length) $ euid ^? _Left) $
       CorrectInterfaceResponseFailure Nothing <$> (getMessageRender <*> pure MsgExamCorrectErrorNeedleTooShort)
 
     matches <- lift . E.select . E.from $ \user -> do
diff --git a/templates/exam-correct.hamlet b/templates/exam-correct.hamlet
index 47ab48deb..309889bc1 100644
--- a/templates/exam-correct.hamlet
+++ b/templates/exam-correct.hamlet
@@ -23,7 +23,7 @@ $newline never
         <tr .table__row #exam-correct__new>
           <td .table__td .uw-exam-correct--date-cell>
           <td .table__td .exam-correct--input-status>
-            <input #exam-correct__user .uw-exam-correct--user-cell type="text" autofocus minLength=3>
+            <input #exam-correct__user .uw-exam-correct--user-cell type="text" autofocus minLength=#{minNeedleLength}>
             <i #exam-correct__user-status .fas .fa-fw>
             <ul #exam-correct__user-candidates>
           $forall ExamPart{examPartNumber} <- examParts