diff --git a/yesod-core/Yesod/Core/Handler.hs b/yesod-core/Yesod/Core/Handler.hs
index cad9e2a8..d054c87e 100644
--- a/yesod-core/Yesod/Core/Handler.hs
+++ b/yesod-core/Yesod/Core/Handler.hs
@@ -253,7 +253,8 @@ import           Data.CaseInsensitive (CI, original)
 import qualified Data.Conduit.List as CL
 import           Control.Monad.Trans.Resource  (MonadResource, InternalState, runResourceT, withInternalState, getInternalState, liftResourceT, resourceForkIO)
 import qualified System.PosixCompat.Files as PC
-import           Data.Conduit (ConduitT, connect, transPipe, Flush (Flush), yield, Void)
+import           Conduit ((.|), runConduit)
+import           Data.Conduit (ConduitT, transPipe, Flush (Flush), yield, Void)
 import qualified Yesod.Core.TypeCache as Cache
 import qualified Data.Word8 as W8
 import qualified Data.Foldable as Fold
@@ -1369,7 +1370,7 @@ fileSource = transPipe liftResourceT . fileSourceRaw
 --
 -- @since 1.6.4
 fileSourceByteString :: MonadResource m => FileInfo -> m S.ByteString
-fileSourceByteString fileInfo = fileSource fileInfo `connect` CL.foldMap id
+fileSourceByteString fileInfo = runConduit $ fileSource fileInfo .| CL.foldMap id
 
 -- | Provide a pure value for the response body.
 --