diff --git a/src/Handler/Corrections.hs b/src/Handler/Corrections.hs
index 72328a5c5..0f33a21f1 100644
--- a/src/Handler/Corrections.hs
+++ b/src/Handler/Corrections.hs
@@ -681,7 +681,7 @@ postCorrectionsCreateR = do
                sheetGroupDesc = Text.intercalate ", " $ map (review _PseudonymText . sheetPseudonymPseudonym) spGroup
               in case sheetGrouping of
           Arbitrary maxSize
-            | genericLength sps > maxSize
+            | genericLength spGroup > maxSize
               -> addMessageI Error $ MsgSheetGroupTooLarge sheetGroupDesc
             | otherwise
               -> do