diff --git a/manifest.dhall b/manifest.dhall
index 4b38bf9dbb52df1d48a855651dbce7b983c4cbb1..64020417e21431b7243fa2d094383f9a024a0031 100644
--- a/manifest.dhall
+++ b/manifest.dhall
@@ -199,6 +199,7 @@ in  [ callHackage "Cabal" "3.8.1.0"
     , callHackage "fcf-containers" "0.7.1"
     , callHackage "finite-field" "0.10.0"
     , callHackage "first-class-families" "0.8.0.1"
+    , callHackage "free" "5.1.9"
     , callHackage "fsnotify" "0.4.1.0"
     , callHackage "foldl" "1.4.12"
     , callHackage "foundation" "0.0.29"
diff --git a/overlay.nix b/overlay.nix
index ac2a8cd2cecc56c17c8dae0dd91077c23105900d..4134a036fe07df2d1203dc926a9b0141974f7492 100644
--- a/overlay.nix
+++ b/overlay.nix
@@ -205,6 +205,8 @@ final: prev: with pkgs.haskell.lib; {
 
   foundation = prev.callPackage (./pkgs/foundation.nix) { };
 
+  free = prev.callPackage (./pkgs/free.nix) { };
+
   fsnotify = prev.callPackage (./pkgs/fsnotify.nix) { };
 
   fuzzy-time = prev.callPackage (./pkgs/fuzzy-time.nix) { };
diff --git a/pkgs/free.nix b/pkgs/free.nix
new file mode 100644
index 0000000000000000000000000000000000000000..6880ce61cbc6a878c8e84ef1cf3d60eb797a06e5
--- /dev/null
+++ b/pkgs/free.nix
@@ -0,0 +1,52 @@
+{ mkDerivation
+, base
+, comonad
+, containers
+, distributive
+, exceptions
+, indexed-traversable
+, lib
+, mtl
+, profunctors
+, semigroupoids
+, template-haskell
+, th-abstraction
+, transformers
+, transformers-base
+}:
+mkDerivation {
+  pname = "free";
+  version = "5.1.9";
+  sha256 = "2e751309408550ebccc2708170ec8473eac1e35b4bc1016bee0776ac938e9fee";
+  revision = "1";
+  editedCabalFile = "133nycxnzy7sgp2vib8hpp2jgzm8pxp31ljf7b4v91jn1gqg3kpl";
+  isLibrary = true;
+  isExecutable = false;
+  enableSeparateDataOutput = false;
+  libraryHaskellDepends = [
+    base
+    comonad
+    containers
+    distributive
+    exceptions
+    indexed-traversable
+    mtl
+    profunctors
+    semigroupoids
+    template-haskell
+    th-abstraction
+    transformers
+    transformers-base
+  ];
+  enableLibraryProfiling = false;
+  enableExecutableProfiling = false;
+  doHaddock = false;
+  jailbreak = true;
+  doCheck = false;
+  doBenchmark = false;
+  hyperlinkSource = false;
+  homepage = "http://github.com/ekmett/free/";
+  description = "Monads for free";
+  license = lib.licenses.bsd3;
+  broken = false;
+}