diff --git a/default.nix b/default.nix
index 5c96bca..7cc6430 100644
--- a/default.nix
+++ b/default.nix
@@ -1,13 +1,13 @@
-{ mkDerivation, aeson, aeson-pretty, ansi-wl-pprint, async, base
-, bytestring, concurrentoutput, containers, cryptonite, data-fix
-, deepseq, directory, exceptions, filepath, foldl, hnix
-, http-client, http-types, lens, lens-aeson, lifted-base, memory
+{ mkDerivation, aeson, aeson-pretty, async, base, bytestring
+, concurrentoutput, containers, cryptonite, data-fix, deepseq
+, directory, exceptions, filepath, foldl, hnix, http-client
+, http-types, lens, lens-aeson, lifted-base, megaparsec, memory
 , mtl, neat-interpolation, network, network-uri, nix-paths
 , optional-args, optparse-applicative, optparse-generic, pooled-io
-, pureMD5, scientific, stdenv, tar, tasty, tasty-golden
-, tasty-hunit, tasty-quickcheck, tasty-smallcheck, temporary, text
-, time, transformers, turtle, unordered-containers, uri-bytestring
-, vector, wreq, zlib
+, prettyprinter, pureMD5, scientific, stdenv, tar, tasty
+, tasty-golden, tasty-hunit, tasty-quickcheck, tasty-smallcheck
+, temporary, text, time, transformers, turtle, unordered-containers
+, uri-bytestring, vector, word8, wreq, zlib
 }:
 mkDerivation {
   pname = "hocker";
@@ -15,23 +15,25 @@ mkDerivation {
   src = ./.;
   isLibrary = true;
   isExecutable = true;
+  enableSeparateDataOutput = true;
   libraryHaskellDepends = [
-    aeson aeson-pretty ansi-wl-pprint async base bytestring
-    concurrentoutput containers cryptonite data-fix deepseq directory
-    exceptions filepath foldl hnix http-client http-types lens
-    lens-aeson lifted-base memory mtl neat-interpolation network
+    aeson aeson-pretty async base bytestring concurrentoutput
+    containers cryptonite data-fix deepseq directory exceptions
+    filepath foldl hnix http-client http-types lens lens-aeson
+    lifted-base megaparsec memory mtl neat-interpolation network
     network-uri nix-paths optparse-applicative optparse-generic
-    pooled-io pureMD5 scientific tar temporary text time transformers
-    turtle unordered-containers uri-bytestring vector wreq zlib
+    pooled-io prettyprinter pureMD5 scientific tar temporary text time
+    transformers turtle unordered-containers uri-bytestring vector wreq
+    zlib
   ];
   executableHaskellDepends = [
     base bytestring cryptonite data-fix filepath hnix lens mtl network
     optional-args optparse-applicative optparse-generic temporary text
   ];
   testHaskellDepends = [
-    aeson ansi-wl-pprint base bytestring containers cryptonite mtl
-    network network-uri tasty tasty-golden tasty-hunit tasty-quickcheck
-    tasty-smallcheck text unordered-containers
+    aeson base bytestring containers cryptonite mtl network network-uri
+    prettyprinter tasty tasty-golden tasty-hunit tasty-quickcheck
+    tasty-smallcheck text unordered-containers word8
   ];
   homepage = "https://github.com/awakesecurity/hocker#readme";
   description = "Interact with the docker registry and generate nix build instructions";
diff --git a/hocker.cabal b/hocker.cabal
index 59dd7d4..0af70e1 100644
--- a/hocker.cabal
+++ b/hocker.cabal
@@ -68,7 +68,6 @@ library
                 base                 >= 4.9 && < 5,
                 aeson                >= 1.0.0.0,
                 aeson-pretty         >= 0.8,
-                ansi-wl-pprint       >= 0.6.7.3,
                 async                >= 2.0.0.0 && < 2.3,
                 bytestring           >= 0.10,
                 concurrentoutput     >= 0.2,
@@ -80,13 +79,13 @@ library
                 exceptions           >= 0.8,
                 filepath             >= 1.4,
                 foldl                >= 1.0,
-                hnix                 >= 0.3.4,
+                hnix                 >= 0.5.2,
                 http-client          >= 0.4,
                 http-types           >= 0.9.1,
                 lens                 >= 4.0,
                 lens-aeson           >= 1.0,
                 lifted-base          >= 0.2.3.8,
-                megaparsec           >= 6.0.0,
+                megaparsec           >= 7.0.0,
                 memory               >= 0.11,
                 mtl                  >= 2.2,
                 neat-interpolation   >= 0.3.2,
@@ -94,6 +93,7 @@ library
                 network-uri          >= 2.6,
                 optparse-applicative >= 0.13,
                 optparse-generic     >= 1.2.0,
+                prettyprinter        >= 1.1.1,
                 pooled-io            >= 0.0.2,
                 pureMD5              >= 2.1,
                 scientific           >= 0.3,
@@ -202,7 +202,7 @@ executable docker2nix
                bytestring           >= 0.10,
                data-fix             >= 0.0.3,
                filepath             >= 1.4,
-               hnix                 >= 0.3.4,
+               hnix                 >= 0.5.2,
                hocker,
                lens                 >= 4.0,
                mtl                  >= 2.2,
@@ -226,7 +226,6 @@ test-suite hocker-tests
   build-depends:
                 base                 >= 4.9 && < 5,
                 aeson                >= 0.9.0.1,
-                ansi-wl-pprint       >= 0.6.7.3,
                 bytestring           >= 0.10,
                 containers           >= 0.5,
                 cryptonite           >= 0.13,
@@ -234,6 +233,7 @@ test-suite hocker-tests
                 mtl                  >= 2.2,
                 network              >= 2.6,
                 network-uri          >= 2.6,
+                prettyprinter        >= 1.1.1,
                 tasty                >= 0.11,
                 tasty-golden         >= 2.3,
                 tasty-hunit          >= 0.9,
diff --git a/nix/17_09.nix b/nix/17_09.nix
deleted file mode 100644
index c264504..0000000
--- a/nix/17_09.nix
+++ /dev/null
@@ -1,9 +0,0 @@
-let
-  fetchNixpkgs = import ./fetchNixpkgs.nix;
-
-in
-  fetchNixpkgs {
-     rev          = "3389f23412877913b9d22a58dfb241684653d7e9";
-     sha256       = "1zf05a90d29bpl7j56y20r3kmrl4xkvg7gsfi55n6bb2r0xp2ma5";
-     outputSha256 = "0wgm7sk9fca38a50hrsqwz6q79z35gqgb9nw80xz7pfdr4jy9pf8";
-  }
diff --git a/nix/18_09.nix b/nix/18_09.nix
new file mode 100644
index 0000000..51fe5b8
--- /dev/null
+++ b/nix/18_09.nix
@@ -0,0 +1,8 @@
+let
+  fetchNixpkgs = import ./fetchNixpkgs.nix;
+
+in
+  fetchNixpkgs {
+     rev          = "f5689d5d6b9be626e8528cb63e2f2cf8f9a0c87e";
+     sha256       = "101f0nnk6i25x9nxviy4by1mpxbdplq81hssvvgi8x54yvh8m3rq";
+  }
diff --git a/nix/Only.nix b/nix/Only.nix
deleted file mode 100644
index 146da3e..0000000
--- a/nix/Only.nix
+++ /dev/null
@@ -1,11 +0,0 @@
-{ mkDerivation, base, deepseq, stdenv }:
-mkDerivation {
-  pname = "Only";
-  version = "0.1";
-  sha256 = "0rdj3a629fk2vp121jq8mf2smkblrz5w3cxhlsyx6my2x29s2ymb";
-  revision = "1";
-  editedCabalFile = "f92f5da97e647451f1ee7f5bf44914fb75062d08ccd3f36b2000d649c63d13aa";
-  libraryHaskellDepends = [ base deepseq ];
-  description = "The 1-tuple type or single-value \"collection\"";
-  license = stdenv.lib.licenses.bsd3;
-}
diff --git a/nix/fetchNixpkgs.nix b/nix/fetchNixpkgs.nix
index dca043e..ddfe51f 100644
--- a/nix/fetchNixpkgs.nix
+++ b/nix/fetchNixpkgs.nix
@@ -1,56 +1,48 @@
 { rev                             # The Git revision of nixpkgs to fetch
-, sha256                          # The SHA256 of the downloaded data
-, outputSha256 ? null             # The SHA256 output hash
+, sha256                          # The SHA256 hash of the unpacked archive
 , system ? builtins.currentSystem # This is overridable if necessary
 }:
 
-with {
-  ifThenElse = { bool, thenValue, elseValue }: (
-    if bool then thenValue else elseValue);
-};
+if (0 <= builtins.compareVersions builtins.nixVersion "1.12")
 
-ifThenElse {
-  bool = (0 <= builtins.compareVersions builtins.nixVersion "1.12");
+# In Nix 1.12, we can just give a `sha256` to `builtins.fetchTarball`.
+then (
+  builtins.fetchTarball {
+    url = "https://github.com/NixOS/nixpkgs/archive/${rev}.tar.gz";
+    inherit sha256;
+  })
 
-  # In Nix 1.12, we can just give a `sha256` to `builtins.fetchTarball`.
-  thenValue = (
-    builtins.fetchTarball {
-      url = "https://github.com/NixOS/nixpkgs/archive/${rev}.tar.gz";
-      sha256 = outputSha256;
-    });
+# This hack should at least work for Nix 1.11
+else (
+  (rec {
+    tarball = import <nix/fetchurl.nix> {
+      url    = "https://github.com/NixOS/nixpkgs/archive/${rev}.tar.gz";
+      sha256 = null;
+    };
 
-  # This hack should at least work for Nix 1.11
-  elseValue = (
-    (rec {
-      tarball = import <nix/fetchurl.nix> {
-        url = "https://github.com/NixOS/nixpkgs/archive/${rev}.tar.gz";
-        inherit sha256;
-      };
-
-      builtin-paths = import <nix/config.nix>;
+    builtin-paths = import <nix/config.nix>;
       
-      script = builtins.toFile "nixpkgs-unpacker" ''
-        "$coreutils/mkdir" "$out"
-        cd "$out"
-        "$gzip" --decompress < "$tarball" | "$tar" -x --strip-components=1
-      '';
+    script = builtins.toFile "nixpkgs-unpacker" ''
+      "$coreutils/mkdir" "$out"
+      cd "$out"
+      "$gzip" --decompress < "$tarball" | "$tar" -x --strip-components=1
+    '';
 
-      nixpkgs = builtins.derivation ({
-        name = "nixpkgs-${builtins.substring 0 6 rev}";
+    nixpkgs = builtins.derivation ({
+      name = "nixpkgs-${builtins.substring 0 6 rev}";
 
-        builder = builtins.storePath builtin-paths.shell;
+      builder = builtins.storePath builtin-paths.shell;
 
-        args = [ script ];
+      args = [ script ];
 
-        inherit tarball system;
+      inherit tarball system;
 
-        tar       = builtins.storePath builtin-paths.tar;
-        gzip      = builtins.storePath builtin-paths.gzip;
-        coreutils = builtins.storePath builtin-paths.coreutils;
-      } // (if null == outputSha256 then { } else {
-        outputHashMode = "recursive";
-        outputHashAlgo = "sha256";
-        outputHash = outputSha256;
-      }));
-    }).nixpkgs);
-}
+      tar       = builtins.storePath builtin-paths.tar;
+      gzip      = builtins.storePath builtin-paths.gzip;
+      coreutils = builtins.storePath builtin-paths.coreutils;
+    } // (if null == sha256 then { } else {
+      outputHashMode = "recursive";
+      outputHashAlgo = "sha256";
+      outputHash = sha256;
+    }));
+  }).nixpkgs)
diff --git a/nix/hnix.nix b/nix/hnix.nix
new file mode 100644
index 0000000..0195cc8
--- /dev/null
+++ b/nix/hnix.nix
@@ -0,0 +1,66 @@
+{ mkDerivation, aeson, array, base, base16-bytestring, binary
+, bytestring, containers, criterion, cryptohash-md5
+, cryptohash-sha1, cryptohash-sha256, cryptohash-sha512, data-fix
+, deepseq, dependent-sum, deriving-compat, Diff, directory
+, exceptions, fetchgit, filepath, free, generic-random, Glob
+, hashable, hashing, haskeline, hedgehog, hspec-discover
+, http-client, http-client-tls, http-types, interpolate
+, lens-family, lens-family-core, lens-family-th, logict, megaparsec
+, monadlist, mtl, optparse-applicative, parser-combinators
+, pretty-show, prettyprinter, process, ref-tf, regex-tdfa
+, regex-tdfa-text, repline, scientific, semigroups, serialise
+, split, stdenv, syb, tasty, tasty-hedgehog, tasty-hunit
+, tasty-quickcheck, tasty-th, template-haskell, text, these, time
+, transformers, unix, unordered-containers, vector, xml
+}:
+mkDerivation {
+  pname = "hnix";
+  version = "0.5.2";
+  src = fetchgit {
+    url = "https://github.com/haskell-nix/hnix.git";
+    sha256 = "0qaknj75bkrgalyvdjz3xwi2n6f2kisq4cpk7cr5198wcy0fn20w";
+    rev = "9b161172a55a70556410e3124e227468fe51dda3";
+    fetchSubmodules = true;
+  };
+  isLibrary = true;
+  isExecutable = true;
+  libraryHaskellDepends = [
+    aeson array base base16-bytestring binary bytestring containers
+    cryptohash-md5 cryptohash-sha1 cryptohash-sha256 cryptohash-sha512
+    data-fix deepseq dependent-sum deriving-compat directory exceptions
+    filepath free hashable hashing haskeline http-client
+    http-client-tls http-types interpolate lens-family lens-family-core
+    lens-family-th logict megaparsec monadlist mtl optparse-applicative
+    parser-combinators pretty-show prettyprinter process ref-tf
+    regex-tdfa regex-tdfa-text scientific semigroups serialise split
+    syb template-haskell text these time transformers unix
+    unordered-containers vector xml
+  ];
+  executableHaskellDepends = [
+    aeson base base16-bytestring bytestring containers cryptohash-md5
+    cryptohash-sha1 cryptohash-sha256 cryptohash-sha512 data-fix
+    deepseq exceptions filepath hashing haskeline mtl
+    optparse-applicative pretty-show prettyprinter repline serialise
+    template-haskell text time transformers unordered-containers
+  ];
+  testHaskellDepends = [
+    base base16-bytestring bytestring containers cryptohash-md5
+    cryptohash-sha1 cryptohash-sha256 cryptohash-sha512 data-fix
+    deepseq dependent-sum Diff directory exceptions filepath
+    generic-random Glob hashing hedgehog interpolate megaparsec mtl
+    optparse-applicative pretty-show prettyprinter process serialise
+    split tasty tasty-hedgehog tasty-hunit tasty-quickcheck tasty-th
+    template-haskell text time transformers unix unordered-containers
+  ];
+  testToolDepends = [ hspec-discover ];
+  benchmarkHaskellDepends = [
+    base base16-bytestring bytestring containers criterion
+    cryptohash-md5 cryptohash-sha1 cryptohash-sha256 cryptohash-sha512
+    data-fix deepseq exceptions filepath hashing mtl
+    optparse-applicative serialise template-haskell text time
+    transformers unordered-containers
+  ];
+  homepage = "https://github.com/haskell-nix/hnix#readme";
+  description = "Haskell implementation of the Nix language";
+  license = stdenv.lib.licenses.bsd3;
+}
diff --git a/nix/http-client-tls.nix b/nix/http-client-tls.nix
deleted file mode 100644
index 1a95faf..0000000
--- a/nix/http-client-tls.nix
+++ /dev/null
@@ -1,19 +0,0 @@
-{ mkDerivation, base, bytestring, case-insensitive, connection
-, cryptonite, data-default-class, exceptions, hspec, http-client
-, http-types, memory, network, stdenv, tls, transformers
-}:
-mkDerivation {
-  pname = "http-client-tls";
-  version = "0.3.3";
-  sha256 = "0r50h7lhrwmxcmiq5nw1rxnpda3k6mhz4jsd86m56ymai5lnf77c";
-  libraryHaskellDepends = [
-    base bytestring case-insensitive connection cryptonite
-    data-default-class exceptions http-client http-types memory network
-    tls transformers
-  ];
-  testHaskellDepends = [ base hspec http-client http-types ];
-  doCheck = false;
-  homepage = "https://github.com/snoyberg/http-client";
-  description = "http-client backend using the connection package and tls library";
-  license = stdenv.lib.licenses.mit;
-}
diff --git a/nix/http-client.nix b/nix/http-client.nix
deleted file mode 100644
index 533186a..0000000
--- a/nix/http-client.nix
+++ /dev/null
@@ -1,27 +0,0 @@
-{ mkDerivation, array, async, base, base64-bytestring
-, blaze-builder, bytestring, case-insensitive, containers, cookie
-, deepseq, directory, exceptions, filepath, ghc-prim, hspec
-, http-types, mime-types, monad-control, network, network-uri
-, random, stdenv, streaming-commons, text, time, transformers, zlib
-}:
-mkDerivation {
-  pname = "http-client";
-  version = "0.5.6.1";
-  sha256 = "1v9bdb8dkhb5g6jl9azk86ig7ia8xh9arr64n7s8r94fp0vl6c1c";
-  libraryHaskellDepends = [
-    array base base64-bytestring blaze-builder bytestring
-    case-insensitive containers cookie deepseq exceptions filepath
-    ghc-prim http-types mime-types network network-uri random
-    streaming-commons text time transformers
-  ];
-  testHaskellDepends = [
-    async base base64-bytestring blaze-builder bytestring
-    case-insensitive containers deepseq directory hspec http-types
-    monad-control network network-uri streaming-commons text time
-    transformers zlib
-  ];
-  doCheck = false;
-  homepage = "https://github.com/snoyberg/http-client";
-  description = "An HTTP client engine";
-  license = stdenv.lib.licenses.mit;
-}
diff --git a/nix/megaparsec.nix b/nix/megaparsec.nix
new file mode 100644
index 0000000..d23e5c5
--- /dev/null
+++ b/nix/megaparsec.nix
@@ -0,0 +1,25 @@
+{ mkDerivation, base, bytestring, case-insensitive, containers
+, criterion, deepseq, hspec, hspec-expectations, mtl
+, parser-combinators, QuickCheck, scientific, stdenv, text
+, transformers, weigh
+}:
+mkDerivation {
+  pname = "megaparsec";
+  version = "7.0.4";
+  sha256 = "325ba5cee8cdef91e351fb2db0b38562f8345b0bcdfed97045671357501de8c1";
+  libraryHaskellDepends = [
+    base bytestring case-insensitive containers deepseq mtl
+    parser-combinators scientific text transformers
+  ];
+  testHaskellDepends = [
+    base bytestring case-insensitive containers hspec
+    hspec-expectations mtl parser-combinators QuickCheck scientific
+    text transformers
+  ];
+  benchmarkHaskellDepends = [
+    base containers criterion deepseq text weigh
+  ];
+  homepage = "https://github.com/mrkkrp/megaparsec";
+  description = "Monadic parser combinators";
+  license = stdenv.lib.licenses.bsd2;
+}
diff --git a/nix/neat-interpolation.nix b/nix/neat-interpolation.nix
new file mode 100644
index 0000000..047f20f
--- /dev/null
+++ b/nix/neat-interpolation.nix
@@ -0,0 +1,15 @@
+{ mkDerivation, base, base-prelude, HTF, megaparsec, stdenv
+, template-haskell, text
+}:
+mkDerivation {
+  pname = "neat-interpolation";
+  version = "0.3.2.4";
+  sha256 = "de7370d938ffd8c7b52d732f4f088387ed8216cf9767d818e99b7ec827931752";
+  libraryHaskellDepends = [
+    base base-prelude megaparsec template-haskell text
+  ];
+  testHaskellDepends = [ base-prelude HTF ];
+  homepage = "https://github.com/nikita-volkov/neat-interpolation";
+  description = "A quasiquoter for neat and simple multiline text interpolation";
+  license = stdenv.lib.licenses.mit;
+}
diff --git a/nix/nix-paths.nix b/nix/nix-paths.nix
deleted file mode 100644
index b33f310..0000000
--- a/nix/nix-paths.nix
+++ /dev/null
@@ -1,11 +0,0 @@
-{ mkDerivation, base, nix, process, stdenv }:
-mkDerivation {
-  pname = "nix-paths";
-  version = "1.0.1";
-  sha256 = "1y09wl1ihxmc9p926g595f70pdcsx78r3q5n5rna23lpq8xicdxb";
-  libraryHaskellDepends = [ base process ];
-  libraryToolDepends = [ nix ];
-  homepage = "https://github.com/peti/nix-paths";
-  description = "Knowledge of Nix's installation directories";
-  license = stdenv.lib.licenses.bsd3;
-}
diff --git a/nix/optparse-applicative.nix b/nix/optparse-applicative.nix
deleted file mode 100644
index bdfc252..0000000
--- a/nix/optparse-applicative.nix
+++ /dev/null
@@ -1,15 +0,0 @@
-{ mkDerivation, ansi-wl-pprint, base, bytestring, process
-, QuickCheck, stdenv, transformers, transformers-compat
-}:
-mkDerivation {
-  pname = "optparse-applicative";
-  version = "0.14.0.0";
-  sha256 = "06iwp1qsq0gjhnhxwyhdhldwvhlgcik6lx5jxpbb40fispyk4nxm";
-  libraryHaskellDepends = [
-    ansi-wl-pprint base process transformers transformers-compat
-  ];
-  testHaskellDepends = [ base bytestring QuickCheck ];
-  homepage = "https://github.com/pcapriotti/optparse-applicative";
-  description = "Utilities and combinators for parsing command line options";
-  license = stdenv.lib.licenses.bsd3;
-}
diff --git a/nix/optparse-generic.nix b/nix/optparse-generic.nix
deleted file mode 100644
index eea0a00..0000000
--- a/nix/optparse-generic.nix
+++ /dev/null
@@ -1,15 +0,0 @@
-{ mkDerivation, base, bytestring, Only, optparse-applicative
-, semigroups, stdenv, system-filepath, text, time, transformers
-, void
-}:
-mkDerivation {
-  pname = "optparse-generic";
-  version = "1.2.3";
-  sha256 = "1wxzpj4xj3bafg3piarwsr69xxzp75fdglx9c3spbahl1aq9wzgk";
-  libraryHaskellDepends = [
-    base bytestring Only optparse-applicative semigroups
-    system-filepath text time transformers void
-  ];
-  description = "Auto-generate a command-line parser for your datatype";
-  license = stdenv.lib.licenses.bsd3;
-}
diff --git a/nix/turtle.nix b/nix/turtle.nix
deleted file mode 100644
index 81c65a9..0000000
--- a/nix/turtle.nix
+++ /dev/null
@@ -1,21 +0,0 @@
-{ mkDerivation, ansi-wl-pprint, async, base, bytestring, clock
-, containers, criterion, directory, doctest, foldl, hostname
-, managed, optional-args, optparse-applicative, process, semigroups
-, stdenv, stm, system-fileio, system-filepath, temporary, text
-, time, transformers, unix, unix-compat
-}:
-mkDerivation {
-  pname = "turtle";
-  version = "1.4.5";
-  sha256 = "082svk0bcf1vvqrzfmb6r5rridgch0c15423fwcb57cfc8xzm8kx";
-  libraryHaskellDepends = [
-    ansi-wl-pprint async base bytestring clock containers directory
-    foldl hostname managed optional-args optparse-applicative process
-    semigroups stm system-fileio system-filepath temporary text time
-    transformers unix unix-compat
-  ];
-  testHaskellDepends = [ base doctest system-filepath temporary ];
-  benchmarkHaskellDepends = [ base criterion text ];
-  description = "Shell programming, Haskell-style";
-  license = stdenv.lib.licenses.bsd3;
-}
diff --git a/nix/wreq.nix b/nix/wreq.nix
deleted file mode 100644
index 5c99ba0..0000000
--- a/nix/wreq.nix
+++ /dev/null
@@ -1,34 +0,0 @@
-{ mkDerivation, aeson, aeson-pretty, attoparsec, authenticate-oauth
-, base, base16-bytestring, base64-bytestring, byteable, bytestring
-, case-insensitive, containers, cryptohash, directory, doctest
-, exceptions, filepath, ghc-prim, hashable, http-client
-, http-client-tls, http-types, HUnit, lens, lens-aeson, mime-types
-, network-info, psqueues, QuickCheck, snap-core, snap-server
-, stdenv, template-haskell, temporary, test-framework
-, test-framework-hunit, test-framework-quickcheck2, text, time
-, time-locale-compat, transformers, unix-compat
-, unordered-containers, uuid, vector
-}:
-mkDerivation {
-  pname = "wreq";
-  version = "0.5.0.1";
-  sha256 = "138n138rczs5xb7pr25b5a2ajhhxph7vfrh02x71w2alh2xr4akc";
-  libraryHaskellDepends = [
-    aeson attoparsec authenticate-oauth base base16-bytestring byteable
-    bytestring case-insensitive containers cryptohash exceptions
-    ghc-prim hashable http-client http-client-tls http-types lens
-    lens-aeson mime-types psqueues template-haskell text time
-    time-locale-compat unordered-containers
-  ];
-  testHaskellDepends = [
-    aeson aeson-pretty base base64-bytestring bytestring
-    case-insensitive containers directory doctest filepath hashable
-    http-client http-types HUnit lens lens-aeson network-info
-    QuickCheck snap-core snap-server temporary test-framework
-    test-framework-hunit test-framework-quickcheck2 text time
-    transformers unix-compat unordered-containers uuid vector
-  ];
-  homepage = "http://www.serpentine.com/wreq";
-  description = "An easy-to-use HTTP client library";
-  license = stdenv.lib.licenses.bsd3;
-}
diff --git a/release.nix b/release.nix
index 9219bc9..708a967 100644
--- a/release.nix
+++ b/release.nix
@@ -7,29 +7,22 @@ let
 
       haskellPackages = oldPkgs.haskellPackages.override {
         overrides = haskellPackagesNew: haskellPackagesOld: {
-
-          optparse-applicative =
+          hnix =
             newPkgs.haskell.lib.dontCheck
-              (haskellPackagesNew.callPackage ./nix/optparse-applicative.nix { });
+              (haskellPackagesNew.callPackage ./nix/hnix.nix { });
 
-          optparse-generic =
-            haskellPackagesNew.callPackage ./nix/optparse-generic.nix { };
+          hocker = haskellPackagesNew.callPackage ./default.nix { };
 
-          turtle =
-            haskellPackagesNew.callPackage ./nix/turtle.nix { };
+          megaparsec = haskellPackagesNew.callPackage ./nix/megaparsec.nix { };
 
-          nix-paths =
-            haskellPackagesNew.callPackage ./nix/nix-paths.nix { };
-
-          hocker =
-            haskellPackagesNew.callPackage ./default.nix { };
+          neat-interpolation = haskellPackagesNew.callPackage ./nix/neat-interpolation.nix { };
         };
       };
 
     })
   ];
 
-  nixpkgs = import ./nix/17_09.nix;
+  nixpkgs = import ./nix/18_09.nix;
 
   pkgs = import nixpkgs { inherit config overlays; };
 
diff --git a/src/Data/Docker/Nix/FetchDocker.hs b/src/Data/Docker/Nix/FetchDocker.hs
index 9da0798..c7cfeeb 100644
--- a/src/Data/Docker/Nix/FetchDocker.hs
+++ b/src/Data/Docker/Nix/FetchDocker.hs
@@ -115,8 +115,6 @@ generate dim@HockerImageMeta{..} = runExceptT $
     pluckedConfigDigest = Hocker.Lib.stripHashId $ manifestJSON ^. key "config" . key "digest" . _String
     pluckedLayerDigests = Hocker.Lib.stripHashId <$> pluckLayersFrom manifestJSON
 
-
-
 {-| Generate a top-level Nix Expression AST from a 'HockerImageMeta'
 record, a config digest, and a list of layer digests.
 
@@ -162,7 +160,8 @@ generateFetchDockerExpr dim@HockerImageMeta{..} configDigest layerDigests = do
         [ ("fetchDockerConfig", Nothing)
         , ("fetchDockerLayer",  Nothing)
         , ("fetchdocker",       Nothing)
-        ]
+        ] -- List keys in sorted order so that we do not care
+          -- whether hnix sorts keys or preserves this order.
 #if MIN_VERSION_hnix(0,5,0)
         False  -- not variadic
 #endif
@@ -175,7 +174,8 @@ mkFetchDocker :: HockerImageMeta -> NExpr -> NExpr -> Either HockerException NEx
 mkFetchDocker HockerImageMeta{..} fetchconfig fetchlayers = do
   registry <- Bifunctor.first mkHockerException serializedRegistry
   pure
-    (mkApp (mkSym constFetchdocker)
+    (mkSym constFetchdocker
+     @@
      (recAttrsE
       [ ("name",        mkStr $ fromMaybe imageName altImageName)
       , ("registry",    mkStr registry)
@@ -201,7 +201,7 @@ mkFetchDocker HockerImageMeta{..} fetchconfig fetchlayers = do
 -- the output expression.
 mkFetchDockerConfig :: Binding NExpr -> Base32Digest -> NExpr
 mkFetchDockerConfig inherits (Base32Digest digest) =
-    mkApp (mkSym constFetchDockerConfig)
+    mkSym constFetchDockerConfig @@
           (Fix $ NSet [ inherits, "sha256" $= (mkStr digest) ])
 
 -- | Generate a list of Nix expression ASTs representing
@@ -228,9 +228,9 @@ mkFetchDockerLayers inherits layerDigests =
   where
     mkLayerId i = Text.pack $ "layer" <> show i
     mkFetchLayer (i, ((Base16Digest d16), (Base32Digest d32))) =
-      (mkLayerId i) $= mkApp (mkSym constFetchDockerLayer)
+      (mkLayerId i) $= (mkSym constFetchDockerLayer @@
                              (Fix $ NSet
                                 [ inherits
                                 , "layerDigest" $= (mkStr d16) -- Required in order to perform a registry request
                                 , "sha256"      $= (mkStr d32) -- Required by Nix for fixed output derivations
-                                ])
+                                ]))
diff --git a/src/Hocker/Lib.hs b/src/Hocker/Lib.hs
index efb9358..ec1274d 100644
--- a/src/Hocker/Lib.hs
+++ b/src/Hocker/Lib.hs
@@ -31,6 +31,10 @@ import           Data.Coerce
 import           Data.Semigroup               ((<>))
 import           Data.Text                    (Text)
 import qualified Data.Text                    as Text
+import           Data.Text.Prettyprint.Doc    (LayoutOptions(..),
+                                               PageWidth(..), SimpleDocStream)
+import qualified Data.Text.Prettyprint.Doc
+import qualified Data.Text.Prettyprint.Doc.Render.Text
 import           Data.Text.Encoding           (encodeUtf8)
 import qualified Network.Wreq                 as Wreq
 import           Nix.Expr                     (NExpr)
@@ -39,9 +43,7 @@ import           System.Directory             (findExecutable)
 import           System.Environment           (getProgName)
 import           System.Exit                  as Exit
 import           System.FilePath.Posix        as File
-import           Text.PrettyPrint.ANSI.Leijen as Text.PrettyPrint (SimpleDoc,
-                                                                   displayS,
-                                                                   renderPretty)
+import qualified System.IO
 import           URI.ByteString
 
 import           Data.Docker.Image.Types
@@ -169,13 +171,19 @@ splitRepository :: ImageName -> (RepoNamePart, ImageNamePart)
 splitRepository (ImageName (Text.pack -> n)) = over _2 Text.tail $ Text.break (=='/') n
 
 -- | Given a nix expression AST, produce a pretty printer document.
-renderNixExpr :: NExpr -> Text.PrettyPrint.SimpleDoc
-renderNixExpr = renderPretty 0.4 120 . prettyNix
+renderNixExpr :: NExpr -> SimpleDocStream ann
+renderNixExpr =
+    Data.Text.Prettyprint.Doc.layoutSmart layoutOptions . prettyNix
+  where
+    layoutOptions = LayoutOptions { layoutPageWidth = AvailablePerLine 120 0.4 }
 
 -- | Print a nix expression AST using the 'renderNixExpr' pretty
 -- printing renderer.
 pprintNixExpr :: NExpr -> IO ()
-pprintNixExpr expr = Prelude.putStrLn (displayS (renderNixExpr expr) "")
+pprintNixExpr expr =
+    Data.Text.Prettyprint.Doc.Render.Text.renderIO System.IO.stdout stream
+  where
+    stream = renderNixExpr expr
 
 -- | Given an executable's name, try to find it in the PATH.
 findExec :: (MonadIO m, Except.MonadError HockerException m)
diff --git a/test/Tests/Data/Docker/Nix/FetchDocker.hs b/test/Tests/Data/Docker/Nix/FetchDocker.hs
index dd5b9e7..5d4177f 100644
--- a/test/Tests/Data/Docker/Nix/FetchDocker.hs
+++ b/test/Tests/Data/Docker/Nix/FetchDocker.hs
@@ -19,6 +19,7 @@ import           Data.ByteString              as BS
 import           Data.ByteString.Lazy.Char8   as C8L
 import           Data.Either                  (either)
 import qualified Data.Text                    as Text
+import qualified Data.Text.Prettyprint.Doc.Render.String
 import           Data.Word8                   as W8
 import           Network.URI
 
@@ -26,7 +27,6 @@ import           Test.Tasty
 import           Test.Tasty.Golden
 import           Test.Tasty.Golden.Advanced   (goldenTest)
 import           Test.Tasty.HUnit
-import           Text.PrettyPrint.ANSI.Leijen as Text.PrettyPrint (displayS)
 import           Text.Printf                  (printf)
 
 import           Data.Docker.Image.Types
@@ -105,7 +105,9 @@ generateFetchDockerNix = do
       , altImageName   = Nothing
       }
 
+  let display = Data.Text.Prettyprint.Doc.Render.String.renderString
+
   either
     (Hocker.Lib.die . Text.pack . show)
-    (return . C8L.pack . (flip displayS "") . Hocker.Lib.renderNixExpr)
+    (return . C8L.pack . display . Hocker.Lib.renderNixExpr)
     nixExpression
diff --git a/test/data/golden-debian_jessie.nix b/test/data/golden-debian_jessie.nix
index 5f6d0de..d14f276 100644
--- a/test/data/golden-debian_jessie.nix
+++ b/test/data/golden-debian_jessie.nix
@@ -1,5 +1,7 @@
-{ fetchDockerConfig, fetchDockerLayer, fetchdocker }:
-fetchdocker rec {
+{ fetchDockerConfig
+  , fetchDockerLayer
+  , fetchdocker }:
+  fetchdocker rec {
     name = "debian";
     registry = "https://registry-1.docker.io/v2/";
     repository = "library";
@@ -8,12 +10,12 @@ fetchdocker rec {
     imageConfig = fetchDockerConfig {
       inherit tag registry repository imageName;
       sha256 = "1rwinmvfc8jxn54y7qnj82acrc97y7xcnn22zaz67y76n4wbwjh5";
-    };
+      };
     imageLayers = let
       layer0 = fetchDockerLayer {
         inherit registry repository imageName;
         layerDigest = "cd0a524342efac6edff500c17e625735bbe479c926439b263bbe3c8518a0849c";
         sha256 = "1744l0c8ag5y7ck9nhr6r5wy9frmaxi7xh80ypgnxb7g891m42nd";
-      };
-      in [ layer0 ];
-  }
\ No newline at end of file
+        };
+    in [ layer0 ];
+    }
\ No newline at end of file