diff --git a/pkgs/development/haskell-modules/configuration-common.nix b/pkgs/development/haskell-modules/configuration-common.nix
index 651c4c8587f..8fec4800601 100644
--- a/pkgs/development/haskell-modules/configuration-common.nix
+++ b/pkgs/development/haskell-modules/configuration-common.nix
@@ -781,9 +781,6 @@ self: super: {
   # Patch to consider NIX_GHC just like xmonad does
   dyre = appendPatch super.dyre ./dyre-nix.patch;
 
-  # https://github.com/gwern/mueval/issues/9
-  mueval = appendPatch (appendPatch super.mueval ./mueval-fix.patch) ./mueval-nix.patch;
-
   # Test suite won't compile against tasty-hunit 0.9.x.
   zlib = dontCheck super.zlib;
 
diff --git a/pkgs/development/haskell-modules/mueval-fix.patch b/pkgs/development/haskell-modules/mueval-fix.patch
deleted file mode 100644
index 62a8f8f61e2..00000000000
--- a/pkgs/development/haskell-modules/mueval-fix.patch
+++ /dev/null
@@ -1,90 +0,0 @@
-diff --git a/Mueval/ArgsParse.hs b/Mueval/ArgsParse.hs
-index 05c8fd9..0c32e27 100644
---- a/Mueval/ArgsParse.hs
-+++ b/Mueval/ArgsParse.hs
-@@ -1,10 +1,9 @@
-+{-# LANGUAGE CPP #-}
- module Mueval.ArgsParse (Options(..), interpreterOpts, getOptions) where
- 
- import Control.Monad (liftM)
- import System.Console.GetOpt
- 
--import qualified Codec.Binary.UTF8.String as Codec (decodeString)
--
- import Mueval.Context (defaultModules, defaultPackages)
- 
- -- | See the results of --help for information on what each option means.
-@@ -98,4 +97,11 @@ header = "Usage: mueval [OPTION...] --expression EXPRESSION..."
- -- | Just give us the end result options; this parsing for
- --   us. Bonus points for handling UTF.
- getOptions :: [String] -> Either (Bool, String) Options
--getOptions = interpreterOpts . map Codec.decodeString
-\ No newline at end of file
-+getOptions = interpreterOpts . map decodeString
-+
-+decodeString :: String -> String
-+#if __GLASGOW_HASKELL__ >= 702
-+decodeString = id
-+#else
-+decodeString = Codec.decodeString
-+#endif
-diff --git a/Mueval/Context.hs b/Mueval/Context.hs
-index 78925cf..548514c 100644
---- a/Mueval/Context.hs
-+++ b/Mueval/Context.hs
-@@ -1,3 +1,4 @@
-+{-# LANGUAGE CPP #-}
- module Mueval.Context (
-   cleanModules,
-   defaultModules,
-@@ -32,7 +33,9 @@ defaultModules = ["Prelude",
-                   "Control.Monad.Error",
-                   "Control.Monad.Fix",
-                   "Control.Monad.Identity",
-+#if !MIN_VERSION_base(4,7,0)
-                   "Control.Monad.Instances",
-+#endif
-                   "Control.Monad.RWS",
-                   "Control.Monad.Reader",
-                   "Control.Monad.State",
-diff --git a/Mueval/Interpreter.hs b/Mueval/Interpreter.hs
-index 29b771f..6c39482 100644
---- a/Mueval/Interpreter.hs
-+++ b/Mueval/Interpreter.hs
-@@ -1,4 +1,5 @@
- {-# LANGUAGE PatternGuards #-}
-+{-# LANGUAGE FlexibleContexts #-}
- -- TODO: suggest the convenience functions be put into Hint proper?
- module Mueval.Interpreter where
- 
-@@ -12,8 +13,6 @@ import System.Exit (exitFailure)
- import System.FilePath.Posix (takeFileName)
- import qualified Control.Exception.Extensible as E (evaluate,catch,SomeException(..))
- 
--import qualified System.IO.UTF8 as UTF (putStrLn)
--
- import Language.Haskell.Interpreter (eval, set, reset, setImportsQ, loadModules, liftIO,
-                                      installedModulesInScope, languageExtensions,
-                                      typeOf, setTopLevelModules, runInterpreter, glasgowExtensions,
-@@ -100,7 +99,7 @@ mvload lfl = do canonfile <- makeRelativeToCurrentDirectory lfl
- -- flooding. Lambdabot has a similar limit.
- sayIO :: String -> IO ()
- sayIO str = do (out,b) <- render 1024 str
--               UTF.putStrLn out
-+               putStrLn out
-                when b exitFailure
- 
- -- | Oh no, something has gone wrong. If it's a compilation error pretty print
-diff --git a/mueval.cabal b/mueval.cabal
-index 3f9406d..b86d796 100644
---- a/mueval.cabal
-+++ b/mueval.cabal
-@@ -32,7 +32,7 @@ library
-         exposed-modules:     Mueval.Parallel, Mueval.Context, Mueval.Interpreter,
-                              Mueval.ArgsParse, Mueval.Resources
-         build-depends:       base>=4 && < 5, containers, directory, mtl>2, filepath, unix, process,
--                             hint>=0.3.1, show>=0.3, utf8-string, Cabal, extensible-exceptions, simple-reflect
-+                             hint>=0.3.1, show>=0.3, Cabal, extensible-exceptions, simple-reflect
-         ghc-options:         -Wall -static
- 
- executable mueval-core
diff --git a/pkgs/development/haskell-modules/mueval-nix.patch b/pkgs/development/haskell-modules/mueval-nix.patch
deleted file mode 100644
index a1f95120a1f..00000000000
--- a/pkgs/development/haskell-modules/mueval-nix.patch
+++ /dev/null
@@ -1,23 +0,0 @@
-diff --git a/Mueval/Interpreter.hs b/Mueval/Interpreter.hs
-index 29b771f..6360ee3 100644
---- a/Mueval/Interpreter.hs
-+++ b/Mueval/Interpreter.hs
-@@ -8,6 +8,7 @@ import Control.Monad.Writer (Any(..),runWriterT,tell)
- import Data.Char (isDigit)
- import Data.List (stripPrefix)
- import System.Directory (copyFile, makeRelativeToCurrentDirectory, removeFile, setCurrentDirectory)
-+import System.Environment (lookupEnv)
- import System.Exit (exitFailure)
- import System.FilePath.Posix (takeFileName)
- import qualified Control.Exception.Extensible as E (evaluate,catch,SomeException(..))
-@@ -47,6 +48,10 @@ interpreter Options { extensions = exts, namedExtensions = nexts,
-                                   -- Explicitly adding ImplicitPrelude because of
-                                   -- http://darcsden.com/jcpetruzza/hint/issue/1
-                                   unless (null lexts) $ set [languageExtensions := (UnknownExtension "ImplicitPrelude" : lexts)]
-+                                  pkgs' <- liftIO $ lookupEnv "NIX_GHC_LIBDIR"
-+                                  case pkgs' of
-+                                    Just pkgs -> unsafeSetGhcOption ("-package-db " ++ pkgs ++ "/package.conf.d")
-+                                    Nothing -> return ()
-                                   when trust $ do
-                                     unsafeSetGhcOption "-fpackage-trust"
-                                     forM_ (trustPkgs >>= words) $ \pkg ->