diff --git a/Network/Wai/Parse.hs b/Network/Wai/Parse.hs
--- a/Network/Wai/Parse.hs
+++ b/Network/Wai/Parse.hs
@@ -29,11 +29,11 @@
 #endif
     ) where
 
+import qualified Data.ByteString.Search as Search
 import qualified Data.ByteString as S
 import qualified Data.ByteString.Lazy as L
 import qualified Data.ByteString.Char8 as S8
 import Data.Word (Word8)
-import Data.Bits
 import Data.Maybe (fromMaybe)
 import Data.List (sortBy)
 import Data.Function (on)
@@ -46,38 +46,11 @@
 import qualified Network.HTTP.Types as H
 import Data.Either (partitionEithers)
 
-uncons :: S.ByteString -> Maybe (Word8, S.ByteString)
-uncons s
-    | S.null s = Nothing
-    | otherwise = Just (S.head s, S.tail s)
-
 breakDiscard :: Word8 -> S.ByteString -> (S.ByteString, S.ByteString)
 breakDiscard w s =
     let (x, y) = S.break (== w) s
      in (x, S.drop 1 y)
 
-qsDecode :: S.ByteString -> S.ByteString
-qsDecode z = fst $ S.unfoldrN (S.length z) go z
-  where
-    go bs =
-        case uncons bs of
-            Nothing -> Nothing
-            Just (43, ws) -> Just (32, ws) -- plus to space
-            Just (37, ws) -> Just $ fromMaybe (37, ws) $ do -- percent
-                (x, xs) <- uncons ws
-                x' <- hexVal x
-                (y, ys) <- uncons xs
-                y' <- hexVal y
-                Just $ (combine x' y', ys)
-            Just (w, ws) -> Just (w, ws)
-    hexVal w
-        | 48 <= w && w <= 57  = Just $ w - 48 -- 0 - 9
-        | 65 <= w && w <= 70  = Just $ w - 55 -- A - F
-        | 97 <= w && w <= 102 = Just $ w - 87 -- a - f
-        | otherwise = Nothing
-    combine :: Word8 -> Word8 -> Word8
-    combine a b = shiftL a 4 .|. b
-
 -- | Parse the HTTP accept string to determine supported content types.
 parseHttpAccept :: S.ByteString -> [S.ByteString]
 parseHttpAccept = map fst
@@ -259,7 +232,7 @@
                     (front, wasFound) <-
                         sinkTillBound bound iter seed
                     let bs = S.concat $ front []
-                    let x' = (name, qsDecode bs)
+                    let x' = (name, bs)
                     return $ C.Emit wasFound [Left x']
                 _ -> do
                     -- ignore this part
@@ -280,8 +253,14 @@
     deriving (Eq, Show)
 
 findBound :: S.ByteString -> S.ByteString -> Bound
-findBound b bs = go [0..S.length bs - 1]
+findBound b bs = handleBreak $ Search.breakOn b bs
   where
+    handleBreak (h, t)
+        | S.null t = go [lowBound..S.length bs - 1]
+        | otherwise = FoundBound h $ S.drop (S.length b) t
+
+    lowBound = max 0 $ S.length bs - S.length b
+
     go [] = NoBound
     go (i:is)
         | mismatch [0..S.length b - 1] [i..S.length bs - 1] = go is
diff --git a/test/WaiExtraTest.hs b/test/WaiExtraTest.hs
--- a/test/WaiExtraTest.hs
+++ b/test/WaiExtraTest.hs
@@ -40,6 +40,8 @@
     it "parseQueryString with question mark" caseParseQueryStringQM
     it "parseHttpAccept" caseParseHttpAccept
     it "parseRequestBody" caseParseRequestBody
+    it "multipart with plus" caseMultipartPlus
+    it "urlencoded with plus" caseUrlEncPlus
     {-
     , it "findBound" caseFindBound
     , it "sinkTillBound" caseSinkTillBound
@@ -168,6 +170,27 @@
         liftIO $ assertEqual "parsing actual post multipart/form-data 2"
                     expected3
                     result3'
+
+caseMultipartPlus :: Assertion
+caseMultipartPlus = do
+    result <- C.runResourceT $ parseRequestBody' lbsBackEnd $ toRequest ctype content
+    liftIO $ result @?= ([("email", "has+plus")], [])
+  where
+    content = S8.pack $
+        "--AaB03x\n" ++
+        "Content-Disposition: form-data; name=\"email\"\n" ++
+        "Content-Type: text/plain; charset=iso-8859-1\n\n" ++
+        "has+plus\n" ++
+        "--AaB03x--"
+    ctype = "multipart/form-data; boundary=AaB03x"
+
+caseUrlEncPlus :: Assertion
+caseUrlEncPlus = do
+    result <- C.runResourceT $ parseRequestBody' lbsBackEnd $ toRequest ctype content
+    liftIO $ result @?= ([("email", "has+plus")], [])
+  where
+    content = S8.pack $ "email=has%2Bplus"
+    ctype = "application/x-www-form-urlencoded"
 
 toRequest :: S8.ByteString -> S8.ByteString -> SRequest
 toRequest ctype content = SRequest defaultRequest
diff --git a/wai-extra.cabal b/wai-extra.cabal
--- a/wai-extra.cabal
+++ b/wai-extra.cabal
@@ -1,5 +1,5 @@
 Name:                wai-extra
-Version:             1.2.0.4
+Version:             1.2.0.5
 Synopsis:            Provides some basic WAI handlers and middleware.
 Description:         The goal here is to provide common features without many dependencies.
 License:             MIT
@@ -39,6 +39,7 @@
                    , blaze-builder-conduit     >= 0.4      && < 0.5
                    , ansi-terminal
                    , resourcet                 >= 0.3      && < 0.4
+                   , stringsearch              >= 0.3      && < 0.4
 
   Exposed-modules:   Network.Wai.Handler.CGI
                      Network.Wai.Middleware.AcceptOverride
@@ -72,7 +73,7 @@
                    , zlib
                    , text
                    , bytestring
-                   , directory 
+                   , directory
                    , zlib-bindings
                    , blaze-builder             >= 0.2.1.4  && < 0.4
                    , data-default