diff --git a/src/Network/WebSockets/Protocol/Hybi00/Internal.hs b/src/Network/WebSockets/Protocol/Hybi00/Internal.hs
--- a/src/Network/WebSockets/Protocol/Hybi00/Internal.hs
+++ b/src/Network/WebSockets/Protocol/Hybi00/Internal.hs
@@ -8,6 +8,7 @@
 import Data.Char (isDigit)
 
 import Data.Binary (encode)
+import Data.ByteString.Lazy.Char8 ()
 import Data.Digest.Pure.MD5 (md5)
 import Data.Int (Int32)
 import qualified Blaze.ByteString.Builder as BB
diff --git a/src/Network/WebSockets/Protocol/Hybi10/Demultiplex.hs b/src/Network/WebSockets/Protocol/Hybi10/Demultiplex.hs
--- a/src/Network/WebSockets/Protocol/Hybi10/Demultiplex.hs
+++ b/src/Network/WebSockets/Protocol/Hybi10/Demultiplex.hs
@@ -17,6 +17,9 @@
 -- | A low-level representation of a WebSocket packet
 data Frame = Frame
     { frameFin     :: !Bool
+    , frameRsv1    :: !Bool
+    , frameRsv2    :: !Bool
+    , frameRsv3    :: !Bool
     , frameType    :: !FrameType
     , framePayload :: !BL.ByteString
     } deriving (Eq, Show)
@@ -42,7 +45,7 @@
 demultiplex :: DemultiplexState
             -> Frame
             -> (Maybe (Message p), DemultiplexState)
-demultiplex state (Frame fin tp pl) = case tp of
+demultiplex state (Frame fin _ _ _ tp pl) = case tp of
     -- Return control messages immediately, they have no influence on the state
     CloseFrame  -> (Just (ControlMessage (Close pl)), state)
     PingFrame   -> (Just (ControlMessage (Ping pl)), state)
diff --git a/src/Network/WebSockets/Protocol/Hybi10/Internal.hs b/src/Network/WebSockets/Protocol/Hybi10/Internal.hs
--- a/src/Network/WebSockets/Protocol/Hybi10/Internal.hs
+++ b/src/Network/WebSockets/Protocol/Hybi10/Internal.hs
@@ -48,12 +48,13 @@
 encodeMessageHybi10 :: Message p -> B.Builder
 encodeMessageHybi10 msg = builder
   where
+    mkFrame = Frame True False False False
     builder = encodeFrameHybi10 $ case msg of
-        (ControlMessage (Close pl)) -> Frame True CloseFrame pl
-        (ControlMessage (Ping pl))  -> Frame True PingFrame pl
-        (ControlMessage (Pong pl))  -> Frame True PongFrame pl
-        (DataMessage (Text pl))     -> Frame True TextFrame pl
-        (DataMessage (Binary pl))   -> Frame True BinaryFrame pl
+        (ControlMessage (Close pl)) -> mkFrame CloseFrame  pl
+        (ControlMessage (Ping pl))  -> mkFrame PingFrame   pl
+        (ControlMessage (Pong pl))  -> mkFrame PongFrame   pl
+        (DataMessage (Text pl))     -> mkFrame TextFrame   pl
+        (DataMessage (Binary pl))   -> mkFrame BinaryFrame pl
 
 -- | Encode a frame
 encodeFrameHybi10 :: Frame -> B.Builder
@@ -61,8 +62,11 @@
     B.fromWord8 byte1 `mappend` len `mappend`
     B.fromLazyByteString (framePayload f)
   where
-    byte0  = fin .|. opcode
-    fin    = if frameFin f then 0x80 else 0x00
+    byte0  = fin .|. rsv1 .|. rsv2 .|. rsv3 .|. opcode
+    fin    = if frameFin f  then 0x80 else 0x00
+    rsv1   = if frameRsv1 f then 0x40 else 0x00
+    rsv2   = if frameRsv2 f then 0x20 else 0x00
+    rsv3   = if frameRsv3 f then 0x10 else 0x00
     opcode = case frameType f of
         ContinuationFrame -> 0x00
         TextFrame         -> 0x01
@@ -91,7 +95,10 @@
 parseFrame :: A.Parser Frame
 parseFrame = do
     byte0 <- anyWord8
-    let fin = byte0 .&. 0x80 == 0x80
+    let fin    = byte0 .&. 0x80 == 0x80
+        rsv1   = byte0 .&. 0x40 == 0x40
+        rsv2   = byte0 .&. 0x20 == 0x20
+        rsv3   = byte0 .&. 0x10 == 0x10
         opcode = byte0 .&. 0x0f
 
     let ft = case opcode of
@@ -116,7 +123,7 @@
 
     chunks <- take64 len
 
-    return $ Frame fin ft (masker $ BL.fromChunks chunks)
+    return $ Frame fin rsv1 rsv2 rsv3 ft (masker $ BL.fromChunks chunks)
   where
     runGet' g = runGet g . BL.fromChunks . return
 
diff --git a/websockets.cabal b/websockets.cabal
--- a/websockets.cabal
+++ b/websockets.cabal
@@ -1,5 +1,5 @@
 Name:    websockets
-Version: 0.6.0.3
+Version: 0.6.0.4
 
 Synopsis:
   A sensible and clean way to write WebSocket-capable servers in Haskell.
@@ -73,7 +73,7 @@
     blaze-builder-enumerator >= 0.2    && < 0.3,
     bytestring               >= 0.9    && < 0.10,
     case-insensitive         >= 0.3    && < 0.5,
-    containers               >= 0.3    && < 0.5,
+    containers               >= 0.3    && < 0.6,
     enumerator               >= 0.4.13 && < 0.5,
     mtl                      >= 2.0    && < 2.2,
     network                  >= 2.3    && < 2.4,
@@ -105,7 +105,7 @@
     blaze-builder-enumerator >= 0.2    && < 0.3,
     bytestring               >= 0.9    && < 0.10,
     case-insensitive         >= 0.3    && < 0.5,
-    containers               >= 0.3    && < 0.5,
+    containers               >= 0.3    && < 0.6,
     enumerator               >= 0.4.13 && < 0.5,
     mtl                      >= 2.0    && < 2.2,
     network                  >= 2.3    && < 2.4,