diff --git a/pkgs/development/libraries/haskell/flexible-defaults/default.nix b/pkgs/development/libraries/haskell/flexible-defaults/default.nix
new file mode 100755
index 00000000000..0b7d4098e49
--- /dev/null
+++ b/pkgs/development/libraries/haskell/flexible-defaults/default.nix
@@ -0,0 +1,13 @@
+{cabal, transformers} :
+
+cabal.mkDerivation (self : {
+  pname = "flexible-defaults";
+  version = "0.0.0.1";
+  sha256 = "07a0gfs9qw1z5j1hq1m4aywgfmg67mkw6pc5xljyip99gvrxdngl";
+  propagatedBuildInputs = [ transformers ];
+  meta = {
+    homepage = "https://github.com/mokus0/flexible-defaults";
+    description = "Generate default function implementations for complex type classes.";
+    license = self.stdenv.lib.licenses.publicDomain;
+  };
+})
diff --git a/pkgs/top-level/haskell-packages.nix b/pkgs/top-level/haskell-packages.nix
index e5a0f225ad9..1c372d9dfeb 100644
--- a/pkgs/top-level/haskell-packages.nix
+++ b/pkgs/top-level/haskell-packages.nix
@@ -517,6 +517,8 @@ let result = let callPackage = x : y : modifyPrio (newScope result.final x y);
 
   feed = callPackage ../development/libraries/haskell/feed {};
 
+  flexibleDefaults = callPackage ../development/libraries/haskell/flexible-defaults {};
+
   filestore = callPackage ../development/libraries/haskell/filestore {};
 
   fgl_5_4_2_2 = callPackage ../development/libraries/haskell/fgl/5.4.2.2.nix {};