diff --git a/nixos/modules/services/mail/nullmailer.nix b/nixos/modules/services/mail/nullmailer.nix
index 55a85a354452..eb982ad00bd7 100644
--- a/nixos/modules/services/mail/nullmailer.nix
+++ b/nixos/modules/services/mail/nullmailer.nix
@@ -1,42 +1,39 @@
 { config, lib, pkgs, ... }:
-
-with lib;
-
 {
 
   options = {
 
     services.nullmailer = {
-      enable = mkOption {
-        type = types.bool;
+      enable = lib.mkOption {
+        type = lib.types.bool;
         default = false;
         description = "Whether to enable nullmailer daemon.";
       };
 
-      user = mkOption {
-        type = types.str;
+      user = lib.mkOption {
+        type = lib.types.str;
         default = "nullmailer";
         description = ''
           User to use to run nullmailer-send.
         '';
       };
 
-      group = mkOption {
-        type = types.str;
+      group = lib.mkOption {
+        type = lib.types.str;
         default = "nullmailer";
         description = ''
           Group to use to run nullmailer-send.
         '';
       };
 
-      setSendmail = mkOption {
-        type = types.bool;
+      setSendmail = lib.mkOption {
+        type = lib.types.bool;
         default = true;
         description = "Whether to set the system sendmail to nullmailer's.";
       };
 
-      remotesFile = mkOption {
-        type = types.nullOr types.str;
+      remotesFile = lib.mkOption {
+        type = lib.types.nullOr lib.types.str;
         default = null;
         description = ''
           Path to the `remotes` control file. This file contains a
@@ -48,8 +45,8 @@ with lib;
       };
 
       config = {
-        adminaddr = mkOption {
-          type = types.nullOr types.str;
+        adminaddr = lib.mkOption {
+          type = lib.types.nullOr lib.types.str;
           default = null;
           description = ''
             If set, all recipients to users at either "localhost" (the literal string)
@@ -61,16 +58,16 @@ with lib;
           '';
         };
 
-        allmailfrom = mkOption {
-          type = types.nullOr types.str;
+        allmailfrom = lib.mkOption {
+          type = lib.types.nullOr lib.types.str;
           default = null;
           description = ''
             If set, content will override the envelope sender on all messages.
           '';
         };
 
-        defaultdomain = mkOption {
-          type = types.nullOr types.str;
+        defaultdomain = lib.mkOption {
+          type = lib.types.nullOr lib.types.str;
           default = null;
           description = ''
              The content of this attribute is appended to any host name that
@@ -80,8 +77,8 @@ with lib;
           '';
         };
 
-        defaulthost = mkOption {
-          type = types.nullOr types.str;
+        defaulthost = lib.mkOption {
+          type = lib.types.nullOr lib.types.str;
           default = null;
           description = ''
              The content of this attribute is appended to any address that
@@ -90,8 +87,8 @@ with lib;
           '';
         };
 
-        doublebounceto = mkOption {
-          type = types.nullOr types.str;
+        doublebounceto = lib.mkOption {
+          type = lib.types.nullOr lib.types.str;
           default = null;
           description = ''
             If the original sender was empty (the original message was a
@@ -100,8 +97,8 @@ with lib;
           '';
         };
 
-        helohost = mkOption {
-          type = types.nullOr types.str;
+        helohost = lib.mkOption {
+          type = lib.types.nullOr lib.types.str;
           default = null;
           description = ''
             Sets  the  environment variable $HELOHOST which is used by the
@@ -110,8 +107,8 @@ with lib;
           '';
         };
 
-        idhost = mkOption {
-          type = types.nullOr types.str;
+        idhost = lib.mkOption {
+          type = lib.types.nullOr lib.types.str;
           default = null;
           description = ''
             The content of this attribute is used when building the message-id
@@ -119,8 +116,8 @@ with lib;
           '';
         };
 
-        maxpause = mkOption {
-          type = with types; nullOr (oneOf [ str int ]);
+        maxpause = lib.mkOption {
+          type = with lib.types; nullOr (oneOf [ str int ]);
           default = null;
           description = ''
              The maximum time to pause between successive queue runs, in seconds.
@@ -128,8 +125,8 @@ with lib;
           '';
         };
 
-        me = mkOption {
-          type = types.nullOr types.str;
+        me = lib.mkOption {
+          type = lib.types.nullOr lib.types.str;
           default = null;
           description = ''
              The fully-qualifiled host name of the computer running nullmailer.
@@ -137,8 +134,8 @@ with lib;
           '';
         };
 
-        pausetime = mkOption {
-          type = with types; nullOr (oneOf [ str int ]);
+        pausetime = lib.mkOption {
+          type = with lib.types; nullOr (oneOf [ str int ]);
           default = null;
           description = ''
             The minimum time to pause between successive queue runs when there
@@ -150,8 +147,8 @@ with lib;
           '';
         };
 
-        remotes = mkOption {
-          type = types.nullOr types.str;
+        remotes = lib.mkOption {
+          type = lib.types.nullOr lib.types.str;
           default = null;
           description = ''
             A list of remote servers to which to send each message. Each line
@@ -167,8 +164,8 @@ with lib;
           '';
         };
 
-        sendtimeout = mkOption {
-          type = with types; nullOr (oneOf [ str int ]);
+        sendtimeout = lib.mkOption {
+          type = with lib.types; nullOr (oneOf [ str int ]);
           default = null;
           description = ''
             The  time to wait for a remote module listed above to complete sending
@@ -183,7 +180,7 @@ with lib;
 
   config = let
     cfg = config.services.nullmailer;
-  in mkIf cfg.enable {
+  in lib.mkIf cfg.enable {
 
     assertions = [
       { assertion = cfg.config.remotes == null || cfg.remotesFile == null;
@@ -194,10 +191,10 @@ with lib;
     environment = {
       systemPackages = [ pkgs.nullmailer ];
       etc = let
-        validAttrs = lib.mapAttrs (_: toString) (filterAttrs (_: value: value != null) cfg.config);
+        validAttrs = lib.mapAttrs (_: toString) (lib.filterAttrs (_: value: value != null) cfg.config);
       in
-        (foldl' (as: name: as // { "nullmailer/${name}".text = validAttrs.${name}; }) {} (attrNames validAttrs))
-          // optionalAttrs (cfg.remotesFile != null) { "nullmailer/remotes".source = cfg.remotesFile; };
+        (lib.foldl' (as: name: as // { "nullmailer/${name}".text = validAttrs.${name}; }) {} (lib.attrNames validAttrs))
+          // lib.optionalAttrs (cfg.remotesFile != null) { "nullmailer/remotes".source = cfg.remotesFile; };
     };
 
     users = {
@@ -234,7 +231,7 @@ with lib;
       };
     };
 
-    services.mail.sendmailSetuidWrapper = mkIf cfg.setSendmail {
+    services.mail.sendmailSetuidWrapper = lib.mkIf cfg.setSendmail {
       program = "sendmail";
       source = "${pkgs.nullmailer}/bin/sendmail";
       owner = cfg.user;