diff --git a/pkgs/development/libraries/haskell/rvar/default.nix b/pkgs/development/libraries/haskell/rvar/default.nix
new file mode 100755
index 000000000000..23956c18df22
--- /dev/null
+++ b/pkgs/development/libraries/haskell/rvar/default.nix
@@ -0,0 +1,15 @@
+{cabal, MonadPrompt, mtl, randomSource, transformers} :
+
+cabal.mkDerivation (self : {
+  pname = "rvar";
+  version = "0.2";
+  sha256 = "1in2qn1clv9b7ijyllhjflh9zdkna31hpyclhlkfnsc6899z3y1f";
+  propagatedBuildInputs = [
+    MonadPrompt mtl randomSource transformers
+  ];
+  meta = {
+    homepage = "https://github.com/mokus0/random-fu";
+    description = "Random Variables";
+    license = self.stdenv.lib.licenses.publicDomain;
+  };
+})
diff --git a/pkgs/top-level/haskell-packages.nix b/pkgs/top-level/haskell-packages.nix
index b6f6ebe16f5d..9f841477c54f 100644
--- a/pkgs/top-level/haskell-packages.nix
+++ b/pkgs/top-level/haskell-packages.nix
@@ -906,6 +906,8 @@ let result = let callPackage = x : y : modifyPrio (newScope result.final x y);
 
   ranges = callPackage ../development/libraries/haskell/ranges {};
 
+  rvar = callPackage ../development/libraries/haskell/rvar {};
+
   readline = callPackage ../development/libraries/haskell/readline {
     inherit (pkgs) readline ncurses;
   };