diff --git a/home/mail/msmtp.nix b/home/mail/msmtp.nix
index 3e725e8..c469982 100644
--- a/home/mail/msmtp.nix
+++ b/home/mail/msmtp.nix
@@ -1,4 +1,4 @@
-{ config, lib, pkgs, ... }:
+{ config, lib, ... }:
 let
   cfg = config.my.home.mail.msmtp;
 in
diff --git a/home/ssh.nix b/home/ssh.nix
index 22f85d3..3bd7f28 100644
--- a/home/ssh.nix
+++ b/home/ssh.nix
@@ -7,7 +7,7 @@ in
     enable = mkDisableOption "ssh configuration";
   };
 
-  config.programs.ssh = {
+  config.programs.ssh = lib.mkIf cfg.enable {
     enable = true;
 
     matchBlocks = {
diff --git a/lib/default.nix b/lib/default.nix
index 9014f85..fa37c23 100644
--- a/lib/default.nix
+++ b/lib/default.nix
@@ -12,8 +12,7 @@ let
   };
 
   mylib = makeExtensible (self:
-    with self; mapModules ./.
-      (file: import file { inherit self lib pkgs inputs; })
+    mapModules ./. (file: import file { inherit self lib pkgs inputs; })
   );
 in
 mylib.extend (self: super:
diff --git a/lib/modules.nix b/lib/modules.nix
index 92e8476..5b8c4c3 100644
--- a/lib/modules.nix
+++ b/lib/modules.nix
@@ -3,21 +3,48 @@ let
   inherit (builtins) readDir pathExists;
   inherit (lib) hasPrefix hasSuffix nameValuePair removeSuffix;
   inherit (self.attrs) mapFilterAttrs;
+
+  implOptionalRecursion = recurse:
+    let
+      recurseStep =
+        if recurse
+        then (n: path: fn: nameValuePair n (impl path fn))
+        else (_: _: _: nameValuePair "" null);
+      impl = dir: fn:
+        mapFilterAttrs
+          (n: _: n != "" && !(hasPrefix "_" n))
+          (n: v:
+            let
+              path = "${toString dir}/${n}";
+            in
+            if v == "directory"
+            then
+              if pathExists "${path}/default.nix"
+              then nameValuePair n (fn path)
+              else recurseStep n path fn
+            else if v == "regular" && n != "default.nix" && hasSuffix ".nix" n
+            then nameValuePair (removeSuffix ".nix" n) (fn path)
+            else nameValuePair "" null)
+          (readDir dir);
+    in
+    impl;
 in
 {
-  mapModules = dir: fn:
-    mapFilterAttrs
-      (n: v:
-        v != null &&
-        !(hasPrefix "_" n))
-      (n: v:
-        let path = "${toString dir}/${n}"; in
-        if v == "directory" && pathExists "${path}/default.nix"
-        then nameValuePair n (fn path)
-        else if v == "regular" &&
-          n != "default.nix" &&
-          hasSuffix ".nix" n
-        then nameValuePair (removeSuffix ".nix" n) (fn path)
-        else nameValuePair "" null)
-      (readDir dir);
+  # Find all nix modules in a directory, discard any prefixed with "_",
+  # map a function to each resulting path, and generate an attribute set
+  # to associate module name to resulting value.
+  #
+  # mapModules ::
+  #   path
+  #   (path -> any)
+  #   attrs
+  mapModules = implOptionalRecursion false;
+
+  # Recursive version of mapModules.
+  #
+  # mapModulesRec ::
+  #   path
+  #   (path -> any)
+  #   attrs
+  mapModulesRec = implOptionalRecursion true;
 }
diff --git a/machines/aramis/default.nix b/machines/aramis/default.nix
index 878f2c9..e2211f4 100644
--- a/machines/aramis/default.nix
+++ b/machines/aramis/default.nix
@@ -2,7 +2,7 @@
 # your system.  Help is available in the configuration.nix(5) man page
 # and in the NixOS manual (accessible by running ‘nixos-help’).
 
-{ config, pkgs, ... }:
+{ ... }:
 
 {
   imports = [
diff --git a/machines/aramis/services.nix b/machines/aramis/services.nix
index 30dc47d..0287c30 100644
--- a/machines/aramis/services.nix
+++ b/machines/aramis/services.nix
@@ -1,4 +1,4 @@
-{ lib, ... }:
+{ ... }:
 {
   config.my.services = {
     wireguard = {
diff --git a/modules/hardware/upower.nix b/modules/hardware/upower.nix
index f21b9d2..95fa282 100644
--- a/modules/hardware/upower.nix
+++ b/modules/hardware/upower.nix
@@ -1,4 +1,4 @@
-{ config, lib, pkgs, ... }:
+{ config, lib, ... }:
 let
   cfg = config.my.hardware.upower;
 in
diff --git a/modules/services/paperless.nix b/modules/services/paperless.nix
index b4e1f44..0e29325 100644
--- a/modules/services/paperless.nix
+++ b/modules/services/paperless.nix
@@ -1,4 +1,4 @@
-{ config, lib, pkgs, ... }:
+{ config, lib, ... }:
 let
   cfg = config.my.services.paperless;
 in
diff --git a/modules/services/podgrab.nix b/modules/services/podgrab.nix
index bc16178..9793d60 100644
--- a/modules/services/podgrab.nix
+++ b/modules/services/podgrab.nix
@@ -1,5 +1,5 @@
 # A simple podcast fetcher
-{ config, lib, pkgs, ... }:
+{ config, lib, ... }:
 let
   cfg = config.my.services.podgrab;
 in
diff --git a/pkgs/nolimips/default.nix b/pkgs/nolimips/default.nix
index 2a1dc33..65d847d 100644
--- a/pkgs/nolimips/default.nix
+++ b/pkgs/nolimips/default.nix
@@ -1,4 +1,4 @@
-{ lib, fetchurl, gnulib, stdenv }:
+{ lib, fetchurl, stdenv }:
 stdenv.mkDerivation rec {
   pname = "nolimips";
   version = "0.11";
diff --git a/pkgs/unbound-zones-adblock/default.nix b/pkgs/unbound-zones-adblock/default.nix
index 845c123..ecec917 100644
--- a/pkgs/unbound-zones-adblock/default.nix
+++ b/pkgs/unbound-zones-adblock/default.nix
@@ -1,4 +1,4 @@
-{ lib, fetchFromGitHub, gawk, stdenvNoCC, unified-hosts-lists }:
+{ lib, gawk, stdenvNoCC, unified-hosts-lists }:
 stdenvNoCC.mkDerivation rec {
   name = "unbound-zones-adblock";
   version = unified-hosts-lists.version;