diff --git a/manifest.dhall b/manifest.dhall
index 54a840c61b69c4079deae2eb772652e8e716cbdd..152829b0114d6efb1ee232fd44e525c84b3a950a 100644
--- a/manifest.dhall
+++ b/manifest.dhall
@@ -181,6 +181,7 @@ in  [ callHackage "Cabal" "3.8.1.0"
         (Some "4eb97c213acf7abe965a3a1b67397199ed155f3c")
         (None Text)
     , callHackage "doctemplates" "0.10.0.2"
+    , callHackage "doctest-parallel" "0.2.5"
     , callCabal2nix
         "double-conversion"
         "https://github.com/haskell/double-conversion"
diff --git a/overlay.nix b/overlay.nix
index 3da84e076bc3e2679b9c063d7566bbf8c4803d7a..09824710ff6219c5be9535dd1addee8a0aacb483 100644
--- a/overlay.nix
+++ b/overlay.nix
@@ -189,6 +189,8 @@ final: prev: with pkgs.haskell.lib; {
 
   doctest = prev.callPackage (./pkgs/doctest.nix) { };
 
+  doctest-parallel = prev.callPackage (./pkgs/doctest-parallel.nix) { };
+
   double-conversion = prev.callPackage (./pkgs/double-conversion.nix) { };
 
   ed25519 = prev.callPackage (./pkgs/ed25519.nix) { };
diff --git a/pkgs/doctest-parallel.nix b/pkgs/doctest-parallel.nix
new file mode 100644
index 0000000000000000000000000000000000000000..d17b8aaeb191d537610a8c4b20dff5b00b27e296
--- /dev/null
+++ b/pkgs/doctest-parallel.nix
@@ -0,0 +1,98 @@
+{ mkDerivation
+, base
+, base-compat
+, Cabal
+, code-page
+, containers
+, deepseq
+, directory
+, exceptions
+, extra
+, filepath
+, ghc
+, ghc-paths
+, Glob
+, hspec
+, hspec-core
+, hspec-discover
+, HUnit
+, lib
+, mockery
+, pretty
+, process
+, QuickCheck
+, random
+, setenv
+, silently
+, stringbuilder
+, syb
+, template-haskell
+, transformers
+, unordered-containers
+}:
+mkDerivation {
+  pname = "doctest-parallel";
+  version = "0.2.5";
+  sha256 = "ec63fdcb9b26084a52d8603d39745abfcfa621b6c99be66803d8bd4ba927be1c";
+  isLibrary = true;
+  isExecutable = false;
+  enableSeparateDataOutput = false;
+  libraryHaskellDepends = [
+    base
+    base-compat
+    Cabal
+    code-page
+    containers
+    deepseq
+    directory
+    exceptions
+    extra
+    filepath
+    ghc
+    ghc-paths
+    Glob
+    pretty
+    process
+    random
+    syb
+    template-haskell
+    transformers
+    unordered-containers
+  ];
+  testHaskellDepends = [
+    base
+    base-compat
+    code-page
+    containers
+    deepseq
+    directory
+    exceptions
+    filepath
+    ghc
+    ghc-paths
+    hspec
+    hspec-core
+    hspec-discover
+    HUnit
+    mockery
+    process
+    QuickCheck
+    setenv
+    silently
+    stringbuilder
+    syb
+    transformers
+  ];
+  testToolDepends = [ hspec-discover ];
+  enableLibraryProfiling = false;
+  enableExecutableProfiling = false;
+  doHaddock = false;
+  jailbreak = true;
+  doCheck = false;
+  doBenchmark = false;
+  hyperlinkSource = false;
+  homepage = "https://github.com/martijnbastiaan/doctest-parallel#readme";
+  description = "Test interactive Haskell examples";
+  license = lib.licenses.mit;
+  broken = false;
+}