diff --git a/LICENSE b/LICENSE
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--- /dev/null
+++ b/LICENSE
@@ -0,0 +1,20 @@
+Copyright (c) 2015 Justin Leitgeb
+
+Permission is hereby granted, free of charge, to any person obtaining
+a copy of this software and associated documentation files (the
+"Software"), to deal in the Software without restriction, including
+without limitation the rights to use, copy, modify, merge, publish,
+distribute, sublicense, and/or sell copies of the Software, and to
+permit persons to whom the Software is furnished to do so, subject to
+the following conditions:
+
+The above copyright notice and this permission notice shall be included
+in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
diff --git a/Setup.hs b/Setup.hs
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--- /dev/null
+++ b/Setup.hs
@@ -0,0 +1,2 @@
+import Distribution.Simple
+main = defaultMain
diff --git a/parseerror-eq.cabal b/parseerror-eq.cabal
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--- /dev/null
+++ b/parseerror-eq.cabal
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+name:                parseerror-eq
+version:             0.1.0.0
+synopsis:            Adds and Eq instance for Parsec's ParseError if needed
+description:
+  .
+  A library to help with compatibility against Parsec versions. Adds an
+  instance of `Eq` to the `ParseError` data type, if it's missing from the
+  version of Parsec that you're compiling against.
+  .
+  To test Parsec's parsing, it's very useful to have an Eq instance for
+  ParseError. This is included in Parsec versions >= 3.1.9, but you need
+  to define it yourself in previous versions.
+  .
+  This simple library conditionally adds an Eq instance for ParseError
+  only if the Parsec version being used is < 3.1.9. To use it, just add
+  parseerror-eq to your cabal dependencies, and in the module where you want
+  to compare ParseErrors,
+  .
+  > import Text.ParseErrorEq ()
+  .
+  The ParseError Eq instance will be imported if it is necessary, otherwise
+  the ParseErrorEq module is empty, so nothing will happen. This ensures that
+  your code that needs the ParseError Eq instance will work regardless of the
+  Parsec version that it is compiled against.
+  .
+homepage:            https://github.com/stackbuilders/parseerror-eq
+license:             MIT
+license-file:        LICENSE
+author:              Justin Leitgeb
+maintainer:          justin@stackbuilders.com
+copyright:           2015 Stack Builders Inc.
+category:            Text
+build-type:          Simple
+cabal-version:       >=1.10
+bug-reports:         https://github.com/stackbuilders/parseerror-eq/issues
+
+library
+  exposed-modules:      Text.ParseErrorEq
+  build-depends:         base >=4.5 && <4.8
+                       , parsec
+
+  hs-source-dirs:      src
+  default-language:    Haskell2010
+  ghc-options:         -Wall
+  default-extensions:  CPP
+
+test-suite parseerror-eq-test
+  type: exitcode-stdio-1.0
+  hs-source-dirs: spec, src
+  main-is: Spec.hs
+  build-depends:       base >=4.5 && <4.8
+                       , parsec
+                       , hspec
+
+  default-language:    Haskell2010
+  ghc-options:         -Wall
+  default-extensions:  CPP
+
+source-repository head
+  type:     git
+  location: git@github.com:stackbuilders/parseerror-eq.git
diff --git a/spec/Spec.hs b/spec/Spec.hs
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--- /dev/null
+++ b/spec/Spec.hs
@@ -0,0 +1,1 @@
+{-# OPTIONS_GHC -F -pgmF hspec-discover #-}
diff --git a/src/Text/ParseErrorEq.hs b/src/Text/ParseErrorEq.hs
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--- /dev/null
+++ b/src/Text/ParseErrorEq.hs
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+{-# OPTIONS_GHC -fno-warn-orphans #-}
+
+{-|
+Module      : Text.ParseErrorEq
+Description : Adds an Eq instance for Parsec's ParseError type if needed
+Copyright   : (c) Stack Builders Inc., 2015
+License     : GPL-3
+Maintainer  : justin@stackbuilders.com
+Stability   : experimental
+Portability : POSIX
+
+This module adds an Eq instance for Parsec's ParseError type if it's
+needed. Import by using (since this module only provides instances):
+
+> import Text.ParseErrorEq ()
+
+For reference, Parsec 3.1.9 adds the Eq instance, in the commit here:
+
+https://github.com/aslatter/parsec/commit/3fb40aaa683fd90f3f0dd9f3c32c6ba707fb24b1
+-}
+module Text.ParseErrorEq where
+
+#if MIN_VERSION_parsec(3,1,9)
+
+-- ParseError Eq instance already defined in Parsec, not necessary to add.
+
+#else
+
+import Text.Parsec.Error (ParseError)
+import Text.ParserCombinators.Parsec.Error
+  (errorPos, errorMessages, messageString)
+
+-- This implementation of Eq for ParseError is the same as the one
+--  added in Parsec in the above commit.
+instance Eq ParseError where
+  l == r
+       = errorPos l == errorPos r && messageStrs l == messageStrs r
+    where messageStrs = map messageString . errorMessages
+
+#endif