diff --git a/ChangeLog.md b/ChangeLog.md
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -1,5 +1,10 @@
 # Revision history for http3
 
+## 0.0.13
+
+* Using OutBodyIface.
+  [#5](https://github.com/kazu-yamamoto/http3/pull/5)
+
 ## 0.0.12
 
 * Catching up http-semantics v0.0.1.
diff --git a/Network/HQ/Server.hs b/Network/HQ/Server.hs
--- a/Network/HQ/Server.hs
+++ b/Network/HQ/Server.hs
@@ -126,7 +126,7 @@
 sendNext :: Stream -> DynaNext -> IO ()
 sendNext strm action = do
     fp <- BS.mallocByteString 2048
-    Next len _reqflush mnext <- withForeignPtr fp $ \buf -> action buf 2048 65536 -- window size
+    Next len _reqflush mnext <- withForeignPtr fp $ \buf -> action buf 2048
     if len == 0
         then return ()
         else do
diff --git a/Network/HTTP3/Send.hs b/Network/HTTP3/Send.hs
--- a/Network/HTTP3/Send.hs
+++ b/Network/HTTP3/Send.hs
@@ -6,7 +6,6 @@
     sendBody,
 ) where
 
-import Data.ByteString.Builder (Builder)
 import qualified Data.ByteString.Builder.Extra as B
 import qualified Data.ByteString.Internal as BS
 import Data.IORef
@@ -53,7 +52,8 @@
             strm
             th
             tlrmkr
-            (\unmask push flush -> unmask $ strmbdy push flush)
+            ( \iface -> outBodyUnmask iface $ strmbdy (outBodyPush iface) (outBodyFlush iface)
+            )
     OutBodyStreamingUnmask strmbdy -> sendStreaming ctx strm th tlrmkr strmbdy
   where
     tlrmkr = outObjTrailers outobj
@@ -73,7 +73,7 @@
     :: TrailersMaker -> DynaNext -> IO (ByteString, Maybe DynaNext, TrailersMaker)
 newByteStringWith tlrmkr0 action = do
     fp <- BS.mallocByteString 2048
-    Next len _reqflush mnext1 <- withForeignPtr fp $ \buf -> action buf 2048 65536 -- window size
+    Next len _reqflush mnext1 <- withForeignPtr fp $ \buf -> action buf 2048
     if len == 0
         then return ("", Nothing, tlrmkr0)
         else do
@@ -104,11 +104,19 @@
     -> Stream
     -> T.Handle
     -> TrailersMaker
-    -> ((forall x. IO x -> IO x) -> (Builder -> IO ()) -> IO () -> IO ())
+    -> (OutBodyIface -> IO ())
     -> IO ()
 sendStreaming ctx strm th tlrmkr0 strmbdy = do
     ref <- newIORef tlrmkr0
-    E.mask $ \unmask -> strmbdy unmask (write ref) flush
+    E.mask $ \unmask -> do
+        let iface =
+                OutBodyIface
+                    { outBodyUnmask = unmask
+                    , outBodyPush = write ref
+                    , outBodyPushFinal = write ref -- fixme
+                    , outBodyFlush = flush
+                    }
+        strmbdy iface
     tlrmkr <- readIORef ref
     Trailers trailers <- tlrmkr Nothing
     unless (null trailers) $ sendHeader ctx strm th trailers
diff --git a/http3.cabal b/http3.cabal
--- a/http3.cabal
+++ b/http3.cabal
@@ -1,6 +1,6 @@
 cabal-version:      2.4
 name:               http3
-version:            0.0.12
+version:            0.0.13
 license:            BSD-3-Clause
 license-file:       LICENSE
 maintainer:         Kazu Yamamoto <kazu@iij.ad.jp>
@@ -81,9 +81,9 @@
         bytestring,
         case-insensitive,
         containers,
-        http-semantics >= 0.0.1,
+        http-semantics >= 0.1 && <0.2,
         http-types,
-        http2 >=5.2 && <5.3,
+        http2 >=5.2.3 && <5.3,
         network,
         network-byte-order,
         quic >= 0.1.20 && < 0.2,