diff --git a/src/Utils/DB.hs b/src/Utils/DB.hs
index de9608a4d..be7ddd292 100644
--- a/src/Utils/DB.hs
+++ b/src/Utils/DB.hs
@@ -99,7 +99,7 @@ updateGetEntity k = fmap (Entity k) . updateGet k
 
 -- | insert or replace a record based on a single uniqueness constraint
 --   this function was meant to be supplied with the uniqueness constraint, but it would be unsafe if the uniqueness constraint would not match the supplied record
-replaceBy :: (PersistUniqueWrite backend, MonadIO m, OnlyOneUniqueKey record, PersistEntityBackend record ~ BaseBackend backend) 
+replaceBy :: (SafeToInsert record, PersistUniqueWrite backend, MonadIO m, OnlyOneUniqueKey record, PersistEntityBackend record ~ BaseBackend backend) 
               => record -> ReaderT backend m ()
 replaceBy r = do 
   u <- onlyUnique r
@@ -158,6 +158,7 @@ checkUniqueKeys (x:xs) = do
 put :: ( MonadIO m
        , PersistUniqueWrite backend
        , PersistRecordBackend record backend
+       , SafeToInsert record
        )
     => record -> ReaderT backend m (Key record)
 -- ^ `insert`, but remove all records with matching uniqueness constraints first
diff --git a/src/Yesod/Core/Instances.hs b/src/Yesod/Core/Instances.hs
index 88f42a5c5..eab7ef562 100644
--- a/src/Yesod/Core/Instances.hs
+++ b/src/Yesod/Core/Instances.hs
@@ -55,7 +55,7 @@ routeToPathPiece
   . renderRoute
 
 
-instance (RenderRoute site, ParseRoute site) => PathPiece (Route site) where
+instance ParseRoute site => PathPiece (Route site) where
   fromPathPiece = routeFromPathPiece
   toPathPiece = routeToPathPiece
 
@@ -71,7 +71,7 @@ instance ParseRoute site => FromJSONKey (Route site) where
 instance RenderRoute site => ToJSONKey (Route site) where
   toJSONKey = toJSONKeyText routeToPathPiece
 
-instance (RenderRoute site, ParseRoute site) => Binary (Route site) where
+instance ParseRoute site => Binary (Route site) where
   put = Binary.put . toPathPiece
   get = Binary.get >>= maybe (fail "Could not parse route") return . fromPathPiece