diff --git a/doctrine/lib/default.nix b/doctrine/lib/default.nix
index 1b03fe1..116bbb8 100644
--- a/doctrine/lib/default.nix
+++ b/doctrine/lib/default.nix
@@ -3,8 +3,18 @@
   doctrine,
   pkgs,
 }: let
-  close = f: args: f (args // {inherit lib pkgs doctrine;});
+  close = vars: f: args:
+    (
+      if builtins.isPath f
+      then import f
+      else f
+    )
+    (args // {inherit lib pkgs doctrine;});
+
+  closeLib = close {inherit lib;};
+  closeFull = close {inherit lib pkgs doctrine;};
 in {
-  importAll = pkgs.callPackage ./importAll.nix {};
-  mkModule = close (import ./mk-module.nix);
+  inherit close;
+  importAll = closeLib ./import-all.nix;
+  mkModule = closeFull ./mk-module.nix;
 }
diff --git a/doctrine/lib/importAll.nix b/doctrine/lib/import-all.nix
similarity index 98%
rename from doctrine/lib/importAll.nix
rename to doctrine/lib/import-all.nix
index 03c5330..423dd9c 100644
--- a/doctrine/lib/importAll.nix
+++ b/doctrine/lib/import-all.nix
@@ -1,4 +1,5 @@
-{lib}: {
+{
+  lib,
   root,
   exclude ? ["default"],
 }:
diff --git a/doctrine/lib/mk-module.nix b/doctrine/lib/mk-module.nix
index 79c24c5..e72ca08 100644
--- a/doctrine/lib/mk-module.nix
+++ b/doctrine/lib/mk-module.nix
@@ -1,18 +1,22 @@
 {
+  # The first few arguments are implicitly passed by the 'close' helper
+  lib,
+  pkgs,
+  doctrine,
   name,
+  config,
   hm ? null,
   sys ? null,
   options ? null,
-  lib,
-  config,
-  pkgs,
-  doctrine,
+  requires ? [],
+  prefix ? doctrine.prefix,
+  namespace ? doctrine.namespace,
 }: let
   optionsSet = import options {
     inherit config lib pkgs cfg name doctrine;
   };
 
-  configSet = import configFiles.${doctrine.namespace} {
+  configSet = import configFiles.${namespace} {
     inherit config lib pkgs doctrine cfg;
   };
 
@@ -20,17 +24,27 @@
     inherit sys hm;
   };
 
-  cfg = config.${doctrine.prefix}.${name};
+  cfg = config.${prefix}.${name};
 in {
   config =
-    lib.optionalAttrs (configFiles ? ${doctrine.namespace})
-    (lib.mkIf cfg.enable configSet);
+    lib.optionalAttrs (configFiles ? ${namespace})
+    (lib.mkIf cfg.enable (lib.mkMerge [
+      configSet
+      {
+        assertions =
+          map (dependency: {
+            assertion = cfg.enable -> config.${prefix}.${dependency}.enable;
+            message = "${prefix}.${name}.enable requires ${prefix}.${dependency}.enable";
+          })
+          requires;
+      }
+    ]));
 
   options = lib.optionalAttrs (options
     != null
-    && optionsSet ? ${doctrine.namespace}) {
-    ${doctrine.prefix}.${name} =
-      optionsSet.${doctrine.namespace}
+    && optionsSet ? ${namespace}) {
+    ${prefix}.${name} =
+      optionsSet.${namespace}
       // {
         enable = lib.mkEnableOption name;
       };
diff --git a/modules/laptop/default.nix b/modules/laptop/default.nix
new file mode 100644
index 0000000..b908d47
--- /dev/null
+++ b/modules/laptop/default.nix
@@ -0,0 +1,10 @@
+{
+  config,
+  doctrine,
+  ...
+}:
+doctrine.lib.mkModule {
+  inherit config;
+  name = "laptop";
+  sys = ./sys.nix;
+}
diff --git a/modules/laptop/sys.nix b/modules/laptop/sys.nix
new file mode 100644
index 0000000..252f49c
--- /dev/null
+++ b/modules/laptop/sys.nix
@@ -0,0 +1,11 @@
+{
+  config,
+  lib,
+  pkgs,
+  ...
+}: {
+  services = {
+    tlp.enable = lib.mkDefault true;
+    upower.enable = lib.mkDefault true;
+  };
+}
diff --git a/modules/thinkpad/default.nix b/modules/thinkpad/default.nix
new file mode 100644
index 0000000..e210947
--- /dev/null
+++ b/modules/thinkpad/default.nix
@@ -0,0 +1,11 @@
+{
+  config,
+  doctrine,
+  ...
+}:
+doctrine.lib.mkModule {
+  inherit config;
+  name = "thinkpad";
+  sys = ./sys.nix;
+  requires = ["laptop"];
+}
diff --git a/modules/thinkpad/sys.nix b/modules/thinkpad/sys.nix
new file mode 100644
index 0000000..bc96146
--- /dev/null
+++ b/modules/thinkpad/sys.nix
@@ -0,0 +1,30 @@
+{
+  config,
+  pkgs,
+  lib,
+  ...
+}: {
+  # For suspending to RAM to work, set Config -> Power -> Sleep State to "Linux" in EFI.
+  # See https://wiki.archlinux.org/index.php/Lenovo_ThinkPad_X1_Carbon_(Gen_6)#Suspend_issues
+  # Fingerprint sensor requires a firmware-update to work.
+
+  boot = {
+    extraModulePackages = with config.boot.kernelPackages; [acpi_call];
+    extraModprobeConfig = "options iwlwifi 11n_disable=1 wd_disable=1";
+
+    # acpi_call makes tlp work for newer thinkpads
+    kernelModules = ["acpi_call"];
+
+    # Force use of the thinkpad_acpi driver for backlight control.
+    # This allows the backlight save/load systemd service to work.
+    kernelParams = ["acpi_backlight=native"];
+  };
+
+  hardware.firmware = [pkgs.sof-firmware];
+
+  services = {
+    fprintd.enable = lib.mkDefault true;
+    thinkfan.enable = lib.mkDefault true;
+    tp-auto-kbbl.enable = lib.mkDefault true;
+  };
+}