diff --git a/manifest.dhall b/manifest.dhall
index 42a31ad22d65a991cfe7f39dcda3f880b7160955..bc02cab03a33f678eedb0dcecd73d2ef69cbea16 100644
--- a/manifest.dhall
+++ b/manifest.dhall
@@ -434,6 +434,7 @@ in  [ callHackage "Cabal" "3.8.1.0"
     , callHackage "microlens-th" "0.4.3.10"
     , callHackage "microlens" "0.4.13.0"
     , callHackage "microstache" "1.0.2.2"
+    , callHackage "mmorph" "1.2.0"
     , callHackage "mod" "0.1.2.2"
     , callHackage "monad-control" "1.0.3.1"
     , callHackage "monad-logger" "0.3.37"
diff --git a/overlay.nix b/overlay.nix
index 7cfca7e1c38d8fa92ccbfba24617c61e7b5799da..320419dbd493528f78f51aae38d11ff3fd00be08 100644
--- a/overlay.nix
+++ b/overlay.nix
@@ -601,6 +601,8 @@ self: with pkgs.haskell.lib; {
 
   microstache = self.callPackage (./pkgs/microstache.nix) { };
 
+  mmorph = self.callPackage (./pkgs/mmorph.nix) { };
+
   mockery = self.callPackage (./pkgs/mockery.nix) { };
 
   mod = self.callPackage (./pkgs/mod.nix) { };
diff --git a/pkgs/mmorph.nix b/pkgs/mmorph.nix
new file mode 100644
index 0000000000000000000000000000000000000000..fb9aa7a03e6eb060846d319cb2a3a06af1be5be0
--- /dev/null
+++ b/pkgs/mmorph.nix
@@ -0,0 +1,33 @@
+{ mkDerivation
+, base
+, lib
+, mtl
+, transformers
+, transformers-compat
+}:
+mkDerivation {
+  pname = "mmorph";
+  version = "1.2.0";
+  sha256 = "61338058eb676b466a462ca45d59f436a77a3bd6b816e4268c6d88522b6a4280";
+  revision = "3";
+  editedCabalFile = "1582vcpjiyimb1vwnhgq8gp805iziwa8sivv2frir0cgq4z236yz";
+  isLibrary = true;
+  isExecutable = false;
+  enableSeparateDataOutput = false;
+  libraryHaskellDepends = [
+    base
+    mtl
+    transformers
+    transformers-compat
+  ];
+  enableLibraryProfiling = false;
+  enableExecutableProfiling = false;
+  doHaddock = false;
+  jailbreak = true;
+  doCheck = false;
+  doBenchmark = false;
+  hyperlinkSource = false;
+  description = "Monad morphisms";
+  license = lib.licenses.bsd3;
+  broken = false;
+}