diff --git a/src/Handler/Participants.hs b/src/Handler/Participants.hs
index 428da5491..65e07da1e 100644
--- a/src/Handler/Participants.hs
+++ b/src/Handler/Participants.hs
@@ -63,7 +63,7 @@ getParticipantsListR = do
 
 getParticipantsR :: TermId -> SchoolId -> Handler TypedContent
 getParticipantsR tid ssh = do
-  csvName <- timestampCsv <*> fmap (flip (addExtension `on` unpack) extensionCsv) (getMessageRender <*> pure (MsgParticipantsCsvName tid ssh))
+  csvName <- timestampCsv <*> fmap ((flip addExtension `on` unpack) extensionCsv) (getMessageRender <*> pure (MsgParticipantsCsvName tid ssh))
   setContentDisposition' $ Just csvName
   respondDefaultOrderedCsvDB $ E.selectSource partQuery .| C.map toParticipantEntry
   where