diff --git a/pkgs/development/libraries/haskell/attoparsec/0.12.0.0.nix b/pkgs/development/libraries/haskell/attoparsec/0.12.0.0.nix
new file mode 100644
index 00000000000..6fd32736c4d
--- /dev/null
+++ b/pkgs/development/libraries/haskell/attoparsec/0.12.0.0.nix
@@ -0,0 +1,21 @@
+{ cabal, deepseq, QuickCheck, scientific, testFramework
+, testFrameworkQuickcheck2, text
+}:
+
+cabal.mkDerivation (self: {
+  pname = "attoparsec";
+  version = "0.12.0.0";
+  sha256 = "04wdb2i2yqybkfnjs3f25nf7xz1nq5sn8z23klbm4xnqaiajmkmr";
+  buildDepends = [ deepseq scientific text ];
+  testDepends = [
+    deepseq QuickCheck scientific testFramework
+    testFrameworkQuickcheck2 text
+  ];
+  meta = {
+    homepage = "https://github.com/bos/attoparsec";
+    description = "Fast combinator parsing for bytestrings and text";
+    license = self.stdenv.lib.licenses.bsd3;
+    platforms = self.ghc.meta.platforms;
+    maintainers = [ self.stdenv.lib.maintainers.andres ];
+  };
+})
diff --git a/pkgs/top-level/haskell-packages.nix b/pkgs/top-level/haskell-packages.nix
index 57cb164866b..a9ed05451fb 100644
--- a/pkgs/top-level/haskell-packages.nix
+++ b/pkgs/top-level/haskell-packages.nix
@@ -195,7 +195,8 @@ self : let callPackage = x : y : modifyPrio (newScope self x y); in
   attoparsec_0_10_4_0 = callPackage ../development/libraries/haskell/attoparsec/0.10.4.0.nix {};
   attoparsec_0_11_3_1 = callPackage ../development/libraries/haskell/attoparsec/0.11.3.1.nix {};
   attoparsec_0_11_3_4 = callPackage ../development/libraries/haskell/attoparsec/0.11.3.4.nix {};
-  attoparsec = self.attoparsec_0_11_3_4;
+  attoparsec_0_12_0_0 = callPackage ../development/libraries/haskell/attoparsec/0.12.0.0.nix {};
+  attoparsec = self.attoparsec_0_12_0_0;
 
   attoparsecBinary = callPackage ../development/libraries/haskell/attoparsec-binary {};