diff --git a/src/Handler/Utils/Exam.hs b/src/Handler/Utils/Exam.hs
index cd834709b..8722255db 100644
--- a/src/Handler/Utils/Exam.hs
+++ b/src/Handler/Utils/Exam.hs
@@ -809,7 +809,7 @@ examAutoOccurrence (hash -> seed) rule ExamAutoOccurrenceConfig{..} occurrences
           return (user, Just occId)
 
 
-deregisterExamUsersCount :: (MonadIO m, HandlerSite m ~ UniWorX, MonadHandler m, MonadCatch m) => ExamId -> [UserId] -> SqlPersistT m Int64
+deregisterExamUsersCount :: (HandlerSite m ~ UniWorX, MonadHandler m, MonadCatch m) => ExamId -> [UserId] -> SqlPersistT m Int64
 deregisterExamUsersCount eId uids = do
   partResults <- E.select . E.from $ \(examPart `E.InnerJoin` examPartResult) -> do
     E.on $ examPart E.^. ExamPartId E.==. examPartResult E.^. ExamPartResultExamPart
@@ -836,7 +836,7 @@ deregisterExamUsersCount eId uids = do
     audit $ TransactionExamDeregister examRegistrationExam examRegistrationUser
     return 1
 
-deregisterExamUsers :: (MonadIO m, HandlerSite m ~ UniWorX, MonadHandler m, MonadCatch m) => ExamId -> [UserId] -> SqlPersistT m ()
+deregisterExamUsers :: (HandlerSite m ~ UniWorX, MonadHandler m, MonadCatch m) => ExamId -> [UserId] -> SqlPersistT m ()
 deregisterExamUsers eId uids = void $ deregisterExamUsersCount eId uids
 
 
diff --git a/src/Handler/Utils/Form.hs b/src/Handler/Utils/Form.hs
index f992e76d8..fccac61b2 100644
--- a/src/Handler/Utils/Form.hs
+++ b/src/Handler/Utils/Form.hs
@@ -172,6 +172,8 @@ data ButtonSubmitDelete = BtnSubmit' | BtnDelete'
 instance Universe ButtonSubmitDelete
 instance Finite ButtonSubmitDelete
 
+nullaryPathPiece ''ButtonSubmitDelete $ camelToPathPiece' 1 . dropSuffix "'"
+
 embedRenderMessage ''UniWorX ''ButtonSubmitDelete $ dropSuffix "'"
 instance Button UniWorX ButtonSubmitDelete where
   btnClasses BtnSubmit' = [BCIsButton, BCPrimary]
@@ -180,8 +182,6 @@ instance Button UniWorX ButtonSubmitDelete where
   btnValidate _ BtnSubmit' = True
   btnValidate _ BtnDelete' = False
 
-nullaryPathPiece ''ButtonSubmitDelete $ camelToPathPiece' 1 . dropSuffix "'"
-
 
 -- | Looks like a button, but is just a link (e.g. for create course, etc.)
 linkButton :: Widget -- ^ Widget to display if unauthorized
diff --git a/src/Handler/Utils/Form/MassInput.hs b/src/Handler/Utils/Form/MassInput.hs
index 7e5d5e7dd..2f409142f 100644
--- a/src/Handler/Utils/Form/MassInput.hs
+++ b/src/Handler/Utils/Form/MassInput.hs
@@ -127,11 +127,11 @@ newtype BoundedPosition coord = BoundedPosition { unBoundedPosition :: coord }
   deriving (Eq, Ord, Generic, Read, Show)
 makeWrapped ''BoundedPosition
 
-instance (LowerBounded coord, PathPiece coord, ToJSON coord, FromJSON coord, ToJSONKey coord, FromJSONKey coord, Ord coord) => IsBoxCoord (BoundedPosition coord) where
+instance (LowerBounded coord, PathPiece coord, ToJSON coord, FromJSON coord, ToJSONKey coord, FromJSONKey coord) => IsBoxCoord (BoundedPosition coord) where
   boxDimensions = [BoxDimension _Wrapped]
   boxOrigin = minBound'
 
-instance (LowerBounded coord, PathPiece coord, ToJSON coord, FromJSON coord, ToJSONKey coord, FromJSONKey coord, Ord coord) => Liveliness (BoundedLiveliness coord) where
+instance (LowerBounded coord, PathPiece coord, ToJSON coord, FromJSON coord, ToJSONKey coord, FromJSONKey coord) => Liveliness (BoundedLiveliness coord) where
   type BoxCoord (BoundedLiveliness coord) = BoundedPosition coord
   liveCoords = iso (Set.mapMonotonic $ view _Wrapped) (Set.mapMonotonic $ view _Unwrapped) . _Unwrapped
 
diff --git a/src/Handler/Utils/Invitations.hs b/src/Handler/Utils/Invitations.hs
index c7f567fe3..adcda4cb9 100644
--- a/src/Handler/Utils/Invitations.hs
+++ b/src/Handler/Utils/Invitations.hs
@@ -45,6 +45,7 @@ class ( PersistRecordBackend junction (YesodPersistBackend UniWorX)
       , Eq (InvitationDBData junction)
       , PersistRecordBackend (InvitationFor junction) (YesodPersistBackend UniWorX)
       , Typeable junction
+      , SafeToInsert junction
       ) => IsInvitableJunction junction where
   -- | One side of the junction is always `User`; `InvitationFor junction` is the other
   type InvitationFor       junction :: Type