diff --git a/modules/tools.nix b/modules/tools.nix
index da58ff4..3d038a8 100644
--- a/modules/tools.nix
+++ b/modules/tools.nix
@@ -1,51 +1,81 @@
-{ pkgs, ... }:
 {
-  environment.systemPackages = with pkgs; [
-    vim
-    git
-    jq
+  lib,
+  options,
+  pkgs,
+  ...
+}:
 
-    # Nix
-    nix-output-monitor # nix build -> nom build
+let
+  htopSettings = {
+    # Header
+    header_margin = false;
+    detailed_cpu_time = true;
+    show_cpu_frequency = true;
+    show_cpu_temperature = true;
+    column_meters_0 = "CPU Memory Swap DiskIO";
+    column_meter_modes_0 = "1 1 1 2";
+    column_meters_1 = "Tasks LoadAverage Uptime NetworkIO";
+    column_meter_modes_1 = "2 2 2 2";
 
-    # Software debug
-    tcpdump
-    lsof
-    ncdu
-    nmap
-    lnav
-    wakeonlan
+    # Tabs
+    "screen:1_Main" =
+      "PID USER PRIORITY NICE M_VIRT M_RESIDENT M_SHARE STATE PERCENT_CPU PERCENT_MEM TIME Command";
+    "screen:2_IO" =
+      "PID USER IO_PRIORITY IO_RATE IO_READ_RATE IO_WRITE_RATE PERCENT_SWAP_DELAY PERCENT_IO_DELAY Command";
 
-    # Hardware info and tunables
-    smartmontools # smartctl
-    usbutils # lsusb
-    pciutils # lspci
-  ];
-
-  programs.htop = {
-    enable = true;
-    settings = {
-      # Header
-      header_margin = false;
-      detailed_cpu_time = true;
-      show_cpu_frequency = true;
-      show_cpu_temperature = true;
-      column_meters_0 = "CPU Memory Swap DiskIO";
-      column_meter_modes_0 = "1 1 1 2";
-      column_meters_1 = "Tasks LoadAverage Uptime NetworkIO";
-      column_meter_modes_1 = "2 2 2 2";
-
-      # Tabs
-      "screen:1_Main" =
-        "PID USER PRIORITY NICE M_VIRT M_RESIDENT M_SHARE STATE PERCENT_CPU PERCENT_MEM TIME Command";
-      "screen:2_IO" =
-        "PID USER IO_PRIORITY IO_RATE IO_READ_RATE IO_WRITE_RATE PERCENT_SWAP_DELAY PERCENT_IO_DELAY Command";
-
-      # List
-      hide_kernel_threads = true;
-      hide_userland_threads = true;
-      highlight_base_name = true;
-      tree_view = true;
-    };
+    # List
+    hide_kernel_threads = true;
+    hide_userland_threads = true;
+    highlight_base_name = true;
+    tree_view = true;
   };
-}
+  hasHtopOption = options ? programs.htop;
+in
+lib.mkMerge [
+  {
+    environment.systemPackages = with pkgs; [
+      vim
+      git
+      jq
+
+      # Nix
+      nix-output-monitor # nix build -> nom build
+
+      # Software debug
+      tcpdump
+      lsof
+      ncdu
+      nmap
+      lnav
+      wakeonlan
+
+      # Hardware info and tunables
+      smartmontools # smartctl
+      usbutils # lsusb
+      pciutils # lspci
+    ];
+  }
+
+  (lib.optionalAttrs hasHtopOption {
+    programs.htop = {
+      enable = true;
+      settings = htopSettings;
+    };
+  })
+
+  (lib.optionalAttrs (!hasHtopOption) {
+    environment.systemPackages = [ pkgs.htop ];
+    environment.etc."htoprc".text =
+      let
+        serialize =
+          val:
+          if lib.isBool val then
+            (if val then "1" else "0")
+          else if lib.isList val then
+            lib.concatStringsSep " " val
+          else
+            toString val;
+      in
+      lib.concatStringsSep "\n" (lib.mapAttrsToList (k: v: "${k}=${serialize v}") htopSettings) + "\n";
+  })
+]