diff --git a/flake.nix b/flake.nix
index 8533768336e16595626cb6df14d037256c7d2aad..102fbbe2d47a824604a90831d5fd4262803da24b 100644
--- a/flake.nix
+++ b/flake.nix
@@ -11,21 +11,35 @@
       let
         overlays = [  ];
         pkgs = nixpkgs.legacyPackages.${system};
+        rsienaMod = pkgs.rPackages.buildRPackage {
+          name = "rsiena";
+          src = pkgs.fetchFromGitHub{
+            owner = "Kaladani";
+            repo = "rsienafork";
+            rev = "37880171c1583f51765c10f0ff6885268103155d";
+            hash = "sha256-w24qqI1ujTJHOOEmswW/b5dRG3dzwgyVXjD93LsuZTI=";
+          };
+          propagatedBuildInputs = with pkgs.rPackages; [ Matrix lattice MASS xtable ];
+        };
         buildInputs = with pkgs; [
           R
-          rPackages.RSiena
+          # rPackages.RSiena
+          rsienaMod
         ];
         name = "run-calc";
         runCalc = (pkgs.writeScriptBin name (builtins.readFile ./test_rsiena_installation.R));
       in rec {
         defaultPackage = packages.runCalc;
-        packages.runCalc = pkgs.symlinkJoin {
-          name = name;
-          paths = [ runCalc ] ++ buildInputs;
+        packages = {
+          RSiena = rsienaMod;
+          runCalc = pkgs.symlinkJoin {
+            name = name;
+            paths = [ runCalc rsienaMod ] ++ buildInputs;
+          };
         };
 
-          devShells.default = pkgs.mkShell {
-            packages = buildInputs ++ [runCalc];
-          };
-        });
+        devShells.default = pkgs.mkShell {
+          packages = [ runCalc rsienaMod ] ++ buildInputs;
+        };
+      });
 }