diff --git a/ChangeLog.md b/ChangeLog.md
new file mode 100644
--- /dev/null
+++ b/ChangeLog.md
@@ -0,0 +1,3 @@
+## 0.4.0
+
+* Hide the `Part` constructor, and allow for additional headers. See: https://github.com/snoyberg/http-client/issues/76
diff --git a/Network/HTTP/Client/MultipartFormData.hs b/Network/HTTP/Client/MultipartFormData.hs
--- a/Network/HTTP/Client/MultipartFormData.hs
+++ b/Network/HTTP/Client/MultipartFormData.hs
@@ -23,7 +23,12 @@
 module Network.HTTP.Client.MultipartFormData
     (
     -- * Part type
-     Part(..)
+     Part
+    ,partName
+    ,partFilename
+    ,partContentType
+    ,partHeaders
+    ,partGetBody
     -- * Constructing parts
     ,partBS
     ,partLBS
@@ -32,6 +37,8 @@
     ,partFileSourceChunked
     ,partFileRequestBody
     ,partFileRequestBodyM
+    -- * Headers
+    ,addPartHeaders
     -- * Building form data
     ,formDataBody
     ,formDataBodyWithBoundary
@@ -45,8 +52,9 @@
 
 import Network.HTTP.Client
 import Network.Mime
-import Network.HTTP.Types (hContentType, methodPost)
+import Network.HTTP.Types (hContentType, methodPost, Header())
 import Data.Monoid ((<>))
+import Data.Foldable (foldMap)
 
 import Blaze.ByteString.Builder
 
@@ -55,6 +63,8 @@
 import qualified Data.ByteString.Lazy as BL
 import qualified Data.ByteString as BS
 
+import qualified Data.CaseInsensitive as CI
+
 import Control.Monad.Trans.State.Strict (state, runState)
 import Control.Monad.IO.Class
 import System.FilePath
@@ -72,12 +82,13 @@
     { partName :: Text -- ^ Name of the corresponding \<input\>
     , partFilename :: Maybe String -- ^ A file name, if this is an attached file
     , partContentType :: Maybe MimeType -- ^ Content type
+    , partHeaders :: [Header] -- ^ List of additional headers
     , partGetBody :: IO RequestBody -- ^ Action in m which returns the body
                                    -- of a message.
     }
 
 instance Show Part where
-    showsPrec d (Part n f c _) =
+    showsPrec d (Part n f c h _) =
         showParen (d>=11) $ showString "Part "
             . showsPrec 11 n
             . showString " "
@@ -85,6 +96,8 @@
             . showString " "
             . showsPrec 11 c
             . showString " "
+            . showsPrec 11 h
+            . showString " "
             . showString "<m (RequestBody m)>"
 
 -- | Make a 'Part' whose content is a strict 'BS.ByteString'.
@@ -94,7 +107,7 @@
 partBS :: Text              -- ^ Name of the corresponding \<input\>.
        -> BS.ByteString     -- ^ The body for this 'Part'.
        -> Part
-partBS n b = Part n mempty mempty $ return $ RequestBodyBS b
+partBS n b = Part n mempty mempty mempty $ return $ RequestBodyBS b
 
 -- | Make a 'Part' whose content is a lazy 'BL.ByteString'.
 --
@@ -103,7 +116,7 @@
 partLBS :: Text             -- ^ Name of the corresponding \<input\>.
         -> BL.ByteString    -- ^ The body for this 'Part'.
         -> Part
-partLBS n b = Part n mempty mempty $ return $ RequestBodyLBS b
+partLBS n b = Part n mempty mempty mempty $ return $ RequestBodyLBS b
 
 -- | Make a 'Part' from a file.
 --
@@ -185,15 +198,19 @@
                      -> IO RequestBody -- ^ Action that will supply data to upload.
                      -> Part
 partFileRequestBodyM n f rqb =
-    Part n (Just f) (Just $ defaultMimeLookup $ pack f) rqb
+    Part n (Just f) (Just $ defaultMimeLookup $ pack f) mempty rqb
 
 {-# INLINE cp #-}
 cp :: BS.ByteString -> RequestBody
 cp bs = RequestBodyBuilder (fromIntegral $ BS.length bs) $ copyByteString bs
 
+-- | Add a list of additional headers to this 'Part'.
+addPartHeaders :: Part -> [Header] -> Part
+addPartHeaders p hs = p { partHeaders = partHeaders p <> hs }
+
 renderPart :: BS.ByteString     -- ^ Boundary between parts.
            -> Part -> IO RequestBody
-renderPart boundary (Part name mfilename mcontenttype get) = liftM render get
+renderPart boundary (Part name mfilename mcontenttype hdrs get) = liftM render get
   where render renderBody =
             cp "--" <> cp boundary <> cp "\r\n"
          <> cp "Content-Disposition: form-data; name=\""
@@ -208,6 +225,11 @@
                         <> cp "Content-Type: "
                         <> cp ct
                 _ -> mempty)
+         <> foldMap (\(k, v) ->
+               cp "\r\n"
+            <> cp (CI.original k)
+            <> cp ": "
+            <> cp v) hdrs
          <> cp "\r\n\r\n"
          <> renderBody <> cp "\r\n"
 
diff --git a/http-client.cabal b/http-client.cabal
--- a/http-client.cabal
+++ b/http-client.cabal
@@ -1,5 +1,5 @@
 name:                http-client
-version:             0.3.8.2
+version:             0.4.0
 synopsis:            An HTTP client engine, intended as a base layer for more user-friendly packages.
 description:         This codebase has been refactored from http-conduit.
 homepage:            https://github.com/snoyberg/http-client
@@ -9,7 +9,7 @@
 maintainer:          michael@snoyman.com
 category:            Network
 build-type:          Simple
-extra-source-files:  README.md
+extra-source-files:  README.md ChangeLog.md
 cabal-version:       >=1.10
 
 flag network-uri