diff --git a/src/Handler/Corrections.hs b/src/Handler/Corrections.hs
index 4984c421a..63867d4d4 100644
--- a/src/Handler/Corrections.hs
+++ b/src/Handler/Corrections.hs
@@ -680,17 +680,15 @@ postCorrectionsCreateR = do
           -> let
                sheetGroupDesc = Text.intercalate ", " $ map (review _PseudonymText . sheetPseudonymPseudonym) spGroup
               in case sheetGrouping of
-          Arbitrary maxSize
-            | genericLength spGroup > maxSize
-              -> addMessageI Error $ MsgSheetGroupTooLarge sheetGroupDesc
-            | otherwise
-              -> do
-                subId <- insert submissionPrototype
-                void . insert $ SubmissionEdit uid now subId
-                insertMany_ . flip map spGroup $ \SheetPseudonym{sheetPseudonymUser} -> SubmissionUser
-                    { submissionUserUser = sheetPseudonymUser
-                    , submissionUserSubmission = subId
-                    }
+          Arbitrary maxSize -> do
+            subId <- insert submissionPrototype
+            void . insert $ SubmissionEdit uid now subId
+            insertMany_ . flip map spGroup $ \SheetPseudonym{sheetPseudonymUser} -> SubmissionUser
+              { submissionUserUser = sheetPseudonymUser
+              , submissionUserSubmission = subId
+              }
+            when (genericLength spGroup > maxSize) $
+              addMessageI Warning $ MsgSheetGroupTooLarge sheetGroupDesc
           RegisteredGroups -> do
             groups <- E.select . E.from $ \submissionGroup -> do
               E.where_ . E.exists . E.from $ \submissionGroupUser ->