diff --git a/nix_flake/flake.lock b/nix_flake/flake.lock
index 41fa965..db71eb0 100644
--- a/nix_flake/flake.lock
+++ b/nix_flake/flake.lock
@@ -50,9 +50,22 @@
       "inputs": {
         "naersk": "naersk",
         "nixpkgs": "nixpkgs_2",
+        "src": "src",
         "utils": "utils"
       }
     },
+    "src": {
+      "flake": false,
+      "locked": {
+        "narHash": "sha256-8vp3LGoPRzhitzLCbTS7QnCz89bsVn48oS2aXIwAmjU=",
+        "path": "..",
+        "type": "path"
+      },
+      "original": {
+        "path": "..",
+        "type": "path"
+      }
+    },
     "utils": {
       "locked": {
         "lastModified": 1648297722,
diff --git a/nix_flake/flake.nix b/nix_flake/flake.nix
index e86a07f..9d2b2e0 100644
--- a/nix_flake/flake.nix
+++ b/nix_flake/flake.nix
@@ -4,9 +4,11 @@
   inputs = {
     utils.url = "github:numtide/flake-utils";
     naersk.url = "github:nix-community/naersk";
+    src.url = "path:..";
+    src.flake = false;
   };
 
-  outputs = { self, nixpkgs, utils, naersk }:
+  outputs = { self, nixpkgs, utils, naersk, src }:
     utils.lib.eachDefaultSystem (system: let
       pkgs = nixpkgs.legacyPackages."${system}";
       naersk-lib = naersk.lib."${system}";
@@ -14,14 +16,15 @@
       # `nix build`
       packages.hallo = naersk-lib.buildPackage {
         pname = "hallo";
-        root = ./..;
+        #root = ./..;
+        root = src;
       };
 
       defaultPackage = packages.hallo;
 
       # NixOS Modules
       nixosModules = {
-        halloSvc = import ./modules/halloSvc.nix;
+        halloSvc = import ./modules/halloSvc.nix self;
       };
 
       # `nix run`
diff --git a/nix_flake/modules/halloSvc.nix b/nix_flake/modules/halloSvc.nix
index 3e3bcd4..40616e0 100644
--- a/nix_flake/modules/halloSvc.nix
+++ b/nix_flake/modules/halloSvc.nix
@@ -1,7 +1,8 @@
-{config, pkgs, lib, hallo, ...}:
+flake: {config, pkgs, lib, hallo, ...}:
 
 let
   cfg = config.services.halloSvc;
+  inherit (flake.packages.${pkgs.stdenv.hostPlatform.system}) hallo;
 in
 
 with lib;
@@ -28,6 +29,13 @@ with lib;
   };
 
   config = mkIf cfg.enable {
+    users.users."${cfg.user}" = {
+      description = "Hallo daemon user";
+      isSystemUser = true;
+      group = "${cfg.user}";
+    };
+    users.groups."${cfg.user}" = {};
+
     systemd.services.halloSvc = {
       wantedBy = [ "multi-user.target" ];
       after = [ "network.target" ];
@@ -35,10 +43,8 @@ with lib;
       serviceConfig = {
         Type = "simple";
         User = "${cfg.user}";
-        ExecStart = ''${hallo.hallo}/bin/hallo'';
+        ExecStart = ''${hallo}/bin/hallo'';
       };
     };
-
-    environment.systemPackages = [ hallo.hello ];
   };
 }
diff --git a/nix_flake/test_vm/flake.lock b/nix_flake/test_vm/flake.lock
index 8a5ec9e..58e28e4 100644
--- a/nix_flake/test_vm/flake.lock
+++ b/nix_flake/test_vm/flake.lock
@@ -19,10 +19,11 @@
       "inputs": {
         "naersk": "naersk",
         "nixpkgs": "nixpkgs_2",
+        "src": "src",
         "utils": "utils"
       },
       "locked": {
-        "narHash": "sha256-LyX46m+YB08861YXrWWmdUTT9uQtyjE96/1beyeETbM=",
+        "narHash": "sha256-4TE+4kf1Q4LqorKsKRrspJYm8iHGX6XtMQLXG5+IN7k=",
         "path": "..",
         "type": "path"
       },
@@ -146,11 +147,11 @@
     },
     "nixpkgs_4": {
       "locked": {
-        "lastModified": 1649024309,
-        "narHash": "sha256-AWbvj/NHZXVwAnHaVOFlxg7tcNerEKrKBmgGfztSHWM=",
+        "lastModified": 1649117019,
+        "narHash": "sha256-ID7nw/8MDgqj/cbJ0wy6AtQ9wp58hSnE6+weZwuHnso=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "af0a9bc0e5341855518e9c1734d7ef913e5138b9",
+        "rev": "ccb90fb9e11459aeaf83cc28d5f8910816d90dd0",
         "type": "github"
       },
       "original": {
@@ -168,6 +169,18 @@
         "nixpkgs": "nixpkgs_4"
       }
     },
+    "src": {
+      "flake": false,
+      "locked": {
+        "narHash": "sha256-8vp3LGoPRzhitzLCbTS7QnCz89bsVn48oS2aXIwAmjU=",
+        "path": "..",
+        "type": "path"
+      },
+      "original": {
+        "path": "..",
+        "type": "path"
+      }
+    },
     "utils": {
       "locked": {
         "lastModified": 1648297722,