diff --git a/src/Handler/Submission.hs b/src/Handler/Submission.hs
index d132683b1..0e7cbe547 100644
--- a/src/Handler/Submission.hs
+++ b/src/Handler/Submission.hs
@@ -486,7 +486,7 @@ submissionHelper tid ssh csh shn mcid = do
             | otherwise -> case change of
               Left subEmail -> deleteInvitation @SubmissionUser smid subEmail
               Right subUid  -> do
-                deleteWhere [SubmissionUserUser ==. subUid]
+                deleteBy $ UniqueSubmissionUser subUid smid
                 audit $ TransactionSubmissionUserDelete smid subUid
           
           addMessageI Success $ if | Nothing <- msmid -> MsgSubmissionCreated