diff --git a/yesod-core/Yesod/Core/Handler.hs b/yesod-core/Yesod/Core/Handler.hs
index d054c87e..c3c19f69 100644
--- a/yesod-core/Yesod/Core/Handler.hs
+++ b/yesod-core/Yesod/Core/Handler.hs
@@ -1362,8 +1362,9 @@ rawRequestBody = do
 fileSource :: MonadResource m => FileInfo -> ConduitT () S.ByteString m ()
 fileSource = transPipe liftResourceT . fileSourceRaw
 
--- | Strict `ByteString` body from `FileInfo`.
--- This function blocking while read file.
+-- | Extract a strict `ByteString` body from a `FileInfo`.
+--
+-- This function will block while reading the file.
 --
 -- > do
 -- >     fileByteString <- fileSourceByteString fileInfo