diff --git a/flake.nix b/flake.nix
index 4c0fcead..605bf123 100644
--- a/flake.nix
+++ b/flake.nix
@@ -46,18 +46,7 @@
             targets.wasm32-unknown-unknown.stable.rust-std
           ];
           craneLib = inputs.crane.lib.${system}.overrideToolchain rustToolchain;
-
-          # TODO reuse in nixos tests
-          cctlConfig = {
-            chainspec = pkgs.fetchurl {
-              url = "https://raw.githubusercontent.com/cspr-rad/casper-node/a8ba82edc949959ea3240f06cc9d64db50d42d64/resources/production/chainspec.toml";
-              hash = "sha256-tStzzhCa/NtmmvMcPjkpB23RN8qhDjAYkMOjo2Tvess=";
-            };
-            config = pkgs.fetchurl {
-              url = "https://raw.githubusercontent.com/cspr-rad/casper-node/53136ac5f004f2ae70a75b4eeb2ff7d907aff6aa/resources/local/config.toml";
-              hash = "sha256-ZuNbxw0nBjuONEZRK8Ru96zZQak4MEQ/eM1fA6esyCM=";
-            };
-          };
+          cctl = inputs'.cctl.packages.cctl.override { casper-node = inputs'.csprpkgs.packages.casper-node; };
 
           kairosContractsAttrs = {
             src = lib.cleanSourceWith {
@@ -180,8 +169,8 @@
 
             PATH_TO_WASM_BINARIES = "${self'.packages.kairos-contracts}/bin";
             PATH_TO_SESSION_BINARIES = "${self'.packages.kairos-session-code}/bin";
-            CCTL_CONFIG = "${cctlConfig.config}";
-            CCTL_CHAINSPEC = "${cctlConfig.chainspec}";
+            CCTL_CONFIG = self'.packages.casper-node-config;
+            CCTL_CHAINSPEC = self'.packages.casper-chainspec;
             KAIROS_SERVER_MIGRATIONS = kairosServerMigrations;
 
             meta.mainProgram = "kairos-server";
@@ -194,8 +183,8 @@
             CARGO_TARGET_WASM32_UNKNOWN_UNKNOWN_LINKER = "lld";
             PATH_TO_WASM_BINARIES = "${self'.packages.kairos-contracts}/bin";
             PATH_TO_SESSION_BINARIES = "${self'.packages.kairos-session-code}/bin";
-            CCTL_CONFIG = "${cctlConfig.config}";
-            CCTL_CHAINSPEC = "${cctlConfig.chainspec}";
+            CCTL_CONFIG = self'.packages.casper-node-config;
+            CCTL_CHAINSPEC = self'.packages.casper-chainspec;
             KAIROS_SERVER_MIGRATIONS = kairosServerMigrations;
             inputsFrom = [ self'.packages.kairos self'.packages.kairos-contracts ];
             packages = [ pkgs.diesel-cli ];
@@ -252,6 +241,15 @@
             kairos-session-code = craneLib.buildPackage (kairosSessionCodeAttrs // {
               pname = "kairos-session-code";
             });
+
+            casper-chainspec = pkgs.fetchurl {
+              url = "https://raw.githubusercontent.com/cspr-rad/casper-node/a8ba82edc949959ea3240f06cc9d64db50d42d64/resources/production/chainspec.toml";
+              hash = "sha256-tStzzhCa/NtmmvMcPjkpB23RN8qhDjAYkMOjo2Tvess=";
+            };
+            casper-node-config = pkgs.fetchurl {
+              url = "https://raw.githubusercontent.com/cspr-rad/casper-node/53136ac5f004f2ae70a75b4eeb2ff7d907aff6aa/resources/local/config.toml";
+              hash = "sha256-ZuNbxw0nBjuONEZRK8Ru96zZQak4MEQ/eM1fA6esyCM=";
+            };
           };
 
           checks = {
diff --git a/nixos/default.nix b/nixos/default.nix
index ad6c74e8..0a153cfc 100644
--- a/nixos/default.nix
+++ b/nixos/default.nix
@@ -48,7 +48,7 @@ in
             ./tests/end-to-end.nix
             {
               inherit mkKairosHostConfig;
-              inherit (self.packages.${pkgs.system}) kairos kairos-contracts casper-client-rs;
+              inherit (self.packages.${pkgs.system}) kairos kairos-contracts casper-client-rs casper-node-config casper-chainspec;
               cctlModule = self.nixosModules.cctl;
             };
       };
diff --git a/nixos/tests/end-to-end.nix b/nixos/tests/end-to-end.nix
index c57cbbe8..9ef6ab28 100644
--- a/nixos/tests/end-to-end.nix
+++ b/nixos/tests/end-to-end.nix
@@ -6,6 +6,8 @@
 , fetchurl
 , casper-client-rs
 , writeShellScript
+, casper-chainspec
+, casper-node-config
 , jq
 }:
 let
@@ -44,14 +46,8 @@ nixosTest {
         port = cctlPort;
         workingDirectory = cctlWorkingDirectory;
         contract = { "${contractHashName}" = kairos-contracts + "/bin/demo-contract-optimized.wasm"; };
-        chainspec = fetchurl {
-          url = "https://raw.githubusercontent.com/cspr-rad/casper-node/53136ac5f004f2ae70a75b4eeb2ff7d907aff6aa/resources/local/chainspec.toml.in";
-          hash = "sha256-b/6c5o3JXFlaTgTHxs8JepaHzjMG75knzlKKqRd/7pc=";
-        };
-        config = fetchurl {
-          url = "https://raw.githubusercontent.com/cspr-rad/casper-node/53136ac5f004f2ae70a75b4eeb2ff7d907aff6aa/resources/local/config.toml";
-          hash = "sha256-ZuNbxw0nBjuONEZRK8Ru96zZQak4MEQ/eM1fA6esyCM=";
-        };
+        chainspec = casper-chainspec;
+        config = casper-node-config;
       };
 
       services.kairos = {