diff --git a/ChangeLog.md b/ChangeLog.md
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -1,5 +1,11 @@
 # Changelog for wai-extra
 
+## 3.0.26
+
+* Throw 413 for too large payload
+* Throw 431 for too large headers
+  [#741](https://github.com/yesodweb/wai/pull/741)
+
 ## 3.0.25
 
 * Supporting `network` version 3.0.
diff --git a/Network/Wai/Parse.hs b/Network/Wai/Parse.hs
--- a/Network/Wai/Parse.hs
+++ b/Network/Wai/Parse.hs
@@ -48,6 +48,7 @@
 #endif
     ) where
 
+import qualified Control.Exception as E
 import qualified Data.ByteString as S
 import qualified Data.ByteString.Lazy as L
 import qualified Data.ByteString.Char8 as S8
@@ -67,6 +68,7 @@
 import Control.Monad.Trans.Resource (allocate, release, register, InternalState, runInternalState)
 import Data.IORef
 import Network.HTTP.Types (hContentType)
+import Network.HTTP2( HTTP2Error (..), ErrorCodeId (..) )
 import Data.CaseInsensitive (mk)
 
 import Prelude hiding (lines)
@@ -426,6 +428,8 @@
 
 
 -- | Take one header or subheader line.
+-- Since:  3.0.26
+--  Throw 431 if headers too large.
 takeLine :: Maybe Int -> Source -> IO (Maybe S.ByteString)
 takeLine maxlen src =
     go ""
@@ -434,7 +438,8 @@
         bs <- readSource src
         case maxlen of
             Just maxlen' -> when (S.length front > maxlen') $
-                error "Header line length exceeds allowed maximum."
+              E.throwIO $ ConnectionError (UnknownErrorCode 431)
+                          "Request Header Fields Too Large"
             Nothing -> return ()
         if S.null bs
             then close front
@@ -450,7 +455,8 @@
                     let res = front `S.append` x
                     case maxlen of
                         Just maxlen' -> when (S.length res > maxlen') $
-                            error "Header line length exceeds allowed maximum."
+                          E.throwIO $ ConnectionError (UnknownErrorCode 431)
+                                    "Request Header Fields Too Large"
                         Nothing -> return ()
                     return $ Just $ killCR $ res
 
@@ -639,8 +645,9 @@
                 cur <- atomicModifyIORef' sref $ \ cur ->
                     let new = cur + fromIntegral (S.length bs) in (new, new)
                 case max' of
-                    Just max'' | cur > max'' -> error "Maximum size exceeded"
-                    _ -> return ()
+                   Just max'' | cur > max'' ->
+                     E.throwIO $ ConnectionError (UnknownErrorCode 413) "Payload Too Large"
+                   _ -> return ()
                 if S.null bs
                     then do
                         writeIORef ref $ WTBDone False
diff --git a/test/Network/Wai/ParseSpec.hs b/test/Network/Wai/ParseSpec.hs
--- a/test/Network/Wai/ParseSpec.hs
+++ b/test/Network/Wai/ParseSpec.hs
@@ -13,6 +13,7 @@
 import qualified Data.Text as TS
 import qualified Data.Text.Encoding as TE
 import           Control.Monad.Trans.Resource (withInternalState, runResourceT)
+import           Network.HTTP2( HTTP2Error (..), ErrorCodeId (..) )
 
 import           Network.Wai
 import           Network.Wai.Test
@@ -94,7 +95,10 @@
   let expectedfile3 = [("yaml", FileInfo "README" "application/octet-stream" "Photo blog using Hack.\n")]
   let expected3 = (expectedsmap3, expectedfile3)
 
+  let unknownErrorException c (ConnectionError (UnknownErrorCode code) _) = c == code
+      unknownErrorException _ _                                           = False
 
+
   let def = defaultParseRequestBodyOptions
   it "parsing actual post multipart/form-data" $ do
     result3 <- parseRequestBody' lbsBackEnd $ toRequest ctype3 content3
@@ -119,17 +123,21 @@
 
   it "exceeding file size" $ do
     SRequest req4 _bod4 <- toRequest'' ctype3 content3
-    (parseRequestBodyEx ( setMaxRequestFileSize 2 def ) lbsBackEnd req4) `shouldThrow` anyErrorCall
+    (parseRequestBodyEx ( setMaxRequestFileSize 2 def ) lbsBackEnd req4)
+      `shouldThrow` unknownErrorException 413
 
   it "exceeding total file size" $ do
     SRequest req4 _bod4 <- toRequest'' ctype3 content3
-    (parseRequestBodyEx ( setMaxRequestFilesSize 20 def ) lbsBackEnd req4) `shouldThrow` anyErrorCall
+    (parseRequestBodyEx ( setMaxRequestFilesSize 20 def ) lbsBackEnd req4)
+      `shouldThrow` unknownErrorException 413
     SRequest req5 _bod5 <- toRequest'' ctype3 content5
-    (parseRequestBodyEx ( setMaxRequestFilesSize 20 def ) lbsBackEnd req5) `shouldThrow` anyErrorCall
+    (parseRequestBodyEx ( setMaxRequestFilesSize 20 def ) lbsBackEnd req5)
+      `shouldThrow` unknownErrorException 413
 
   it "exceeding max parm value size" $ do
     SRequest req4 _bod4 <- toRequest'' ctype2 content2
-    (parseRequestBodyEx ( setMaxRequestParmsSize 10 def ) lbsBackEnd req4) `shouldThrow` anyErrorCall
+    (parseRequestBodyEx ( setMaxRequestParmsSize 10 def ) lbsBackEnd req4)
+      `shouldThrow` unknownErrorException 413
 
   it "exceeding max header lines" $ do
     SRequest req4 _bod4 <- toRequest'' ctype2 content2
@@ -137,7 +145,8 @@
 
   it "exceeding header line size" $ do
     SRequest req4 _bod4 <- toRequest'' ctype3 content4
-    (parseRequestBodyEx ( setMaxHeaderLineLength 8190 def ) lbsBackEnd req4) `shouldThrow` anyErrorCall
+    (parseRequestBodyEx ( setMaxHeaderLineLength 8190 def ) lbsBackEnd req4)
+      `shouldThrow` unknownErrorException 431
 
   it "Testing parseRequestBodyEx with application/x-www-form-urlencoded" $ do
     let content = "thisisalongparameterkey=andthisbeanevenlongerparametervaluehelloworldhowareyou"
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:             3.0.25
+Version:             3.0.26
 Synopsis:            Provides some basic WAI handlers and middleware.
 description:
   Provides basic WAI handler and middleware functionality:
@@ -115,6 +115,7 @@
                    , zlib
                    , aeson
                    , iproute
+                   , http2
 
   if os(windows)
       cpp-options:   -DWINDOWS
@@ -202,6 +203,7 @@
                    , cookie
                    , time
                    , case-insensitive
+                   , http2
     ghc-options:     -Wall
     default-language:          Haskell2010