diff --git a/manifest.dhall b/manifest.dhall
index f5bae53c2cf91cea99bfcdc63b043134a28bb198..58d47933dc4d477dc3404e806671206602cc81d1 100644
--- a/manifest.dhall
+++ b/manifest.dhall
@@ -314,6 +314,7 @@ in  [ callHackage "Cabal" "3.8.1.0"
     , callHackage "hackage-db" "2.1.2"
     , callHackage "hackage-security" "0.6.2.2"
     , callHackage "haddock-library" "1.11.0"
+    , callHackage "happy" "1.20.0"
     , callHackage "hashable" "1.4.1.0"
     , callHackage "hashing" "0.1.0.1"
     , callHackage "hashtables" "1.3"
diff --git a/overlay.nix b/overlay.nix
index 0c31ca04556339cac15cdfe68b1fd4ac1102c6a0..10c53898e3fbfa8fdc62b6299c153e7803d52331 100644
--- a/overlay.nix
+++ b/overlay.nix
@@ -433,6 +433,8 @@ self: with pkgs.haskell.lib; {
 
   haddock-library = self.callPackage (./pkgs/haddock-library.nix) { };
 
+  happy = self.callPackage (./pkgs/happy.nix) { };
+
   hashable = self.callPackage (./pkgs/hashable.nix) { };
 
   hashing = self.callPackage (./pkgs/hashing.nix) { };
diff --git a/pkgs/happy.nix b/pkgs/happy.nix
new file mode 100644
index 0000000000000000000000000000000000000000..5896ef4c45d8b73f75e3a7ffe92fafd19e0fa757
--- /dev/null
+++ b/pkgs/happy.nix
@@ -0,0 +1,25 @@
+{ mkDerivation, array, base, containers, lib, mtl, process }:
+mkDerivation {
+  pname = "happy";
+  version = "1.20.0";
+  sha256 = "3b1d3a8f93a2723b554d9f07b2cd136be1a7b2fcab1855b12b7aab5cbac8868c";
+  revision = "1";
+  editedCabalFile = "16dy1cv942rizxp8slnnbwi5l24ggsmy38madbin9scz38idqisx";
+  isLibrary = false;
+  isExecutable = true;
+  enableSeparateDataOutput = true;
+  executableHaskellDepends = [ array base containers mtl ];
+  testHaskellDepends = [ base process ];
+  enableLibraryProfiling = false;
+  enableExecutableProfiling = false;
+  doHaddock = false;
+  jailbreak = true;
+  doCheck = false;
+  doBenchmark = false;
+  hyperlinkSource = false;
+  homepage = "https://www.haskell.org/happy/";
+  description = "Happy is a parser generator for Haskell";
+  license = lib.licenses.bsd2;
+  mainProgram = "happy";
+  broken = false;
+}