diff --git a/etc/default.nix b/etc/default.nix
index dd219dc74ef..9a168f19f6a 100644
--- a/etc/default.nix
+++ b/etc/default.nix
@@ -50,13 +50,6 @@ import ../helpers/make-etc.nix {
       target = "hosts";
     }
 
-    { # Name Service Switch configuration file.  Required by the C library.
-      source = if config.services.avahi.nssmdns
-               then (assert config.services.avahi.enable; ./nsswitch-mdns.conf)
-               else ./nsswitch.conf;
-      target = "nsswitch.conf";
-    }
-
     { # Friendly greeting on the virtual consoles.
       source = pkgs.writeText "issue" ''
       
diff --git a/system/options.nix b/system/options.nix
index 605eb3618ee..7299af54443 100644
--- a/system/options.nix
+++ b/system/options.nix
@@ -347,8 +347,7 @@ in
         let
           list2 =
              list
-          ++ pkgs.lib.optional config.users.ldap.enable pkgs.nss_ldap
-          ++ pkgs.lib.optional config.services.avahi.nssmdns pkgs.nssmdns;
+          ++ pkgs.lib.optional config.users.ldap.enable pkgs.nss_ldap;
         in {
           list = list2;
           path = pkgs.lib.makeLibraryPath list2;
@@ -1039,66 +1038,6 @@ in
       };
     };
 
-    avahi = {
-
-      enable = mkOption {
-        default = false;
-        description = ''
-          Whether to run the Avahi daemon, which allows Avahi clients
-          to use Avahi's service discovery facilities and also allows
-          the local machine to advertise its presence and services
-          (through the mDNS responder implemented by `avahi-daemon').
-        '';
-      };
-
-      hostName = mkOption {
-        default = "nixos";  # XXX: Would be nice to use `networking.hostName'.
-        description = ''Host name advertised on the LAN.'';
-      };
-
-      browseDomains = mkOption {
-        default = [ "0pointer.de" "zeroconf.org" ];
-        description = ''
-          List of non-local DNS domains to be browsed.
-        '';
-      };
-
-      ipv4 = mkOption {
-        default = true;
-        description = ''Whether to use IPv4'';
-      };
-
-      ipv6 = mkOption {
-        default = false;
-        description = ''Whether to use IPv6'';
-      };
-
-      wideArea = mkOption {
-        default = true;
-        description = ''Whether to enable wide-area service discovery.'';
-      };
-
-      publishing = mkOption {
-        default = true;
-        description = ''Whether to allow publishing.'';
-      };
-
-      nssmdns = mkOption {
-        default = false;
-        description = ''
-          Whether to enable the mDNS NSS (Name Service Switch) plug-in.
-          Enabling it allows applications to resolve names in the `.local'
-          domain by transparently querying the Avahi daemon.
-
-          Warning: Currently, enabling this option breaks DNS lookups after
-          a `nixos-rebuild'.  This is because `/etc/nsswitch.conf' is
-          updated to use `nss-mdns' but `libnss_mdns' is not in
-          applications' `LD_LIBRARY_PATH'.  The next time `/etc/profile' is
-          sourced, it will set up an appropriate `LD_LIBRARY_PATH', though.
-        '';
-      };
-    };
-
     bitlbee = {
 
       enable = mkOption {
@@ -1930,19 +1869,6 @@ in
     };
 
 
-    dbus = {
-
-      enable = mkOption {
-        default = true;
-        description = "
-          Whether to start the D-Bus message bus daemon.  It is required
-          by the HAL service.
-        ";
-      };
-
-    };
-
-
     udev = {
 
       addFirmware = mkOption {
@@ -3007,6 +2933,8 @@ root        ALL=(ALL) SETENV: ALL
     (import ../upstart-jobs/pcmcia.nix)
 
     # services
+    (import ../upstart-jobs/avahi-daemon.nix)
+    (import ../upstart-jobs/dbus.nix)
     (import ../upstart-jobs/hal.nix)
     (import ../upstart-jobs/gpm.nix)
     (import ../upstart-jobs/nagios/default.nix)
diff --git a/system/system.nix b/system/system.nix
index 5e831f24425..a102b6f012b 100644
--- a/system/system.nix
+++ b/system/system.nix
@@ -160,7 +160,6 @@ rec {
   ++ pkgs.lib.optional config.security.sudo.enable pkgs.sudo
   ++ pkgs.lib.optional config.services.atd.enable pkgs.at
   ++ pkgs.lib.optional config.services.bitlbee.enable pkgs.bitlbee
-  ++ pkgs.lib.optional config.services.avahi.enable pkgs.avahi
   ++ pkgs.lib.optional config.networking.defaultMailServer.directDelivery pkgs.ssmtp 
   ++ config.environment.extraPackages
   ++ pkgs.lib.optional config.fonts.enableFontDir fontDir
diff --git a/upstart-jobs/avahi-daemon.nix b/upstart-jobs/avahi-daemon.nix
index 5b5ae2d2f65..45146d2a850 100644
--- a/upstart-jobs/avahi-daemon.nix
+++ b/upstart-jobs/avahi-daemon.nix
@@ -1,8 +1,83 @@
-{avahi, config, writeText, lib}:
+# Avahi daemon.
+{pkgs, config}:
 
+###### interface
 let
+  inherit (pkgs.lib) mkOption;
 
-  avahiDaemonConf = with config; writeText "avahi-daemon.conf" ''
+  options = {
+    services = {
+      avahi = {
+
+        enable = mkOption {
+          default = false;
+          description = ''
+            Whether to run the Avahi daemon, which allows Avahi clients
+            to use Avahi's service discovery facilities and also allows
+            the local machine to advertise its presence and services
+            (through the mDNS responder implemented by `avahi-daemon').
+          '';
+        };
+
+        hostName = mkOption {
+          default = "nixos";  # XXX: Would be nice to use `networking.hostName'.
+          description = ''Host name advertised on the LAN.'';
+        };
+
+        browseDomains = mkOption {
+          default = [ "0pointer.de" "zeroconf.org" ];
+          description = ''
+            List of non-local DNS domains to be browsed.
+          '';
+        };
+
+        ipv4 = mkOption {
+          default = true;
+          description = ''Whether to use IPv4'';
+        };
+
+        ipv6 = mkOption {
+          default = false;
+          description = ''Whether to use IPv6'';
+        };
+
+        wideArea = mkOption {
+          default = true;
+          description = ''Whether to enable wide-area service discovery.'';
+        };
+
+        publishing = mkOption {
+          default = true;
+          description = ''Whether to allow publishing.'';
+        };
+
+        nssmdns = mkOption {
+          default = false;
+          description = ''
+            Whether to enable the mDNS NSS (Name Service Switch) plug-in.
+            Enabling it allows applications to resolve names in the `.local'
+            domain by transparently querying the Avahi daemon.
+
+            Warning: Currently, enabling this option breaks DNS lookups after
+            a `nixos-rebuild'.  This is because `/etc/nsswitch.conf' is
+            updated to use `nss-mdns' but `libnss_mdns' is not in
+            applications' `LD_LIBRARY_PATH'.  The next time `/etc/profile' is
+            sourced, it will set up an appropriate `LD_LIBRARY_PATH', though.
+          '';
+        };
+      };
+    };
+  };
+in
+
+###### implementation
+let
+  cfg = config.services.avahi;
+  ifEnable = pkgs.lib.ifEnable cfg.enable;
+
+  inherit (pkgs) avahi writeText lib;
+
+  avahiDaemonConf = with cfg; writeText "avahi-daemon.conf" ''
     [server]
     host-name=${hostName}
     browse-domains=${lib.concatStringsSep ", " browseDomains}
@@ -16,33 +91,74 @@ let
     disable-publishing=${if publishing then "no" else "yes"}
   '';
 
+  user = {
+    name = "avahi";
+    uid = (import ../system/ids.nix).uids.avahi;
+    description = "`avahi-daemon' privilege separation user";
+    home = "/var/empty";
+  };
+
+  group = {
+    name = "avahi";
+    gid = (import ../system/ids.nix).gids.avahi;
+  };
+
+  job = {
+    name = "avahi-daemon";
+
+    job = ''
+      start on network-interfaces/started
+      stop on network-interfaces/stop
+      respawn
+      script
+        export PATH="${avahi}/bin:${avahi}/sbin:$PATH"
+        exec ${avahi}/sbin/avahi-daemon --daemonize -f "${avahiDaemonConf}"
+      end script
+    '';
+  };
 in
 
 {
-  name = "avahi-daemon";
-  
-  users = [
-    { name = "avahi";
-      uid = (import ../system/ids.nix).uids.avahi;
-      description = "`avahi-daemon' privilege separation user";
-      home = "/var/empty";
-    }
+  require = [
+    (import ../upstart-jobs/default.nix) # config.services.extraJobs
+    # (import ../system/?) # system.nssModules
+    # (import ?) # config.environment.etc
+    # (import ../system/user.nix) # users.*
+    # (import ../upstart-jobs/udev.nix) # services.udev.*
+    (import ../upstart-jobs/dbus.nix) # services.dbus.*
+    # (import ?) # config.environment.extraPackages
+    options
   ];
 
-  groups = [
-    { name = "avahi";
-      gid = (import ../system/ids.nix).gids.avahi;
-    }
-  ];
+  system = {
+    nssModules = ifEnable (pkgs.lib.optional
+      cfg.nssmdns pkgs.nssmdns
+    );
+  };
 
-  job = ''
-    start on network-interfaces/started
-    stop on network-interfaces/stop
-    respawn
-    script
-      export PATH="${avahi}/bin:${avahi}/sbin:$PATH"
-      exec ${avahi}/sbin/avahi-daemon --daemonize -f "${avahiDaemonConf}"
-    end script
-  '';
+  environment = {
+    extraPackages = ifEnable [avahi];
 
-}
+    # Name Service Switch configuration file.  Required by the C library.
+    etc = [{
+      source = if cfg.nssmdns
+               then (assert cfg.enable; ../etc/nsswitch-mdns.conf)
+               else ../etc/nsswitch.conf;
+      target = "nsswitch.conf";
+    }];
+  };
+
+  users = {
+    extraUsers = ifEnable [user];
+    extraGroups = ifEnable [group];
+  };
+
+  services = {
+    extraJobs = ifEnable [job];
+
+    dbus = {
+      enable = cfg.enable;
+      services = ifEnable [avahi];
+    };
+  };
+}
\ No newline at end of file
diff --git a/upstart-jobs/dbus.nix b/upstart-jobs/dbus.nix
index a8ce1fddf06..0edb1183bcf 100644
--- a/upstart-jobs/dbus.nix
+++ b/upstart-jobs/dbus.nix
@@ -1,6 +1,40 @@
-{stdenv, dbus, dbusServices ? []}:
+# D-Bus system-wide daemon.
+{pkgs, config}:
 
+###### interface
 let
+  inherit (pkgs.lib) mkOption;
+
+  options = {
+    services = {
+      dbus = {
+
+        enable = mkOption {
+          default = true;
+          description = "
+            Whether to start the D-Bus message bus daemon.  It is required
+            by the HAL service.
+          ";
+          merge = pkgs.lib.mergeEnableOption;
+        };
+
+        services = mkOption {
+          default = [];
+          description = ".. fill me ..";
+        };
+
+      };
+    };
+  };
+in
+
+###### implementation
+let
+  cfg = config.services.dbus;
+  ifEnable = pkgs.lib.ifEnable cfg.enable;
+  services = cfg.services;
+
+  inherit (pkgs) stdenv dbus;
 
   homeDir = "/var/run/dbus";
 
@@ -14,49 +48,66 @@ let
         --replace '<fork/>' ''
 
       ensureDir $out/system.d
-      for i in ${toString dbusServices}; do
+      for i in ${toString services}; do
         ln -s $i/etc/dbus-1/system.d/* $out/system.d/
       done
     ";
   };
 
+  user = {
+    name = "messagebus";
+    uid = (import ../system/ids.nix).uids.messagebus;
+    description = "D-Bus system message bus daemon user";
+    home = homeDir;
+  };
+
+  job = {
+    name = "dbus";
+  
+    job = ''
+      description "D-Bus system message bus daemon"
+
+      start on startup
+      stop on shutdown
+
+      start script
+
+          mkdir -m 0755 -p ${homeDir}
+          chown messagebus ${homeDir}
+
+          mkdir -m 0755 -p /var/lib/dbus
+          ${dbus.tools}/bin/dbus-uuidgen --ensure
+
+      end script
+
+      respawn
+
+      script
+          rm -f ${homeDir}/pid
+          exec ${dbus}/bin/dbus-daemon --config-file=${configFile}/system.conf
+      end script
+    '';
+  };
+
 in
 
 {
-  name = "dbus";
-  
-  users = [
-    { name = "messagebus";
-      uid = (import ../system/ids.nix).uids.messagebus;
-      description = "D-Bus system message bus daemon user";
-      home = homeDir;
-    }
+  require = [
+    (import ../upstart-jobs/default.nix) # config.services.extraJobs
+    # (import ../system/user.nix) # users.*
+    # (import ?) # config.environment.extraPackages
+    options
   ];
-  
-  extraPath = [dbus.daemon dbus.tools];
-  
-  job = ''
-    description "D-Bus system message bus daemon"
 
-    start on startup
-    stop on shutdown
+  environment = {
+    extraPackages = ifEnable [dbus.daemon dbus.tools];
+  };
 
-    start script
+  users = {
+    extraUsers = ifEnable [user];
+  };
 
-        mkdir -m 0755 -p ${homeDir}
-        chown messagebus ${homeDir}
-
-        mkdir -m 0755 -p /var/lib/dbus
-        ${dbus.tools}/bin/dbus-uuidgen --ensure
-
-    end script
-
-    respawn
-
-    script
-        rm -f ${homeDir}/pid
-        exec ${dbus}/bin/dbus-daemon --config-file=${configFile}/system.conf
-    end script
-  '';
-  
+  services = {
+    extraJobs = ifEnable [job];
+  };
 }
diff --git a/upstart-jobs/default.nix b/upstart-jobs/default.nix
index cb2035c66dc..490424b0c6d 100644
--- a/upstart-jobs/default.nix
+++ b/upstart-jobs/default.nix
@@ -272,13 +272,6 @@ let
       inherit (pkgs) makePortmap;
      })
 
-  # Avahi daemon.
-  ++ optional config.services.avahi.enable
-    (import ../upstart-jobs/avahi-daemon.nix {
-      inherit (pkgs) avahi writeText lib;
-      config = config.services.avahi;
-    })
-
   # X server.
   ++ optional config.services.xserver.enable
     (import ../upstart-jobs/xserver.nix {
@@ -388,18 +381,6 @@ let
       inherit (pkgs) alsaUtils;
     })
 
-  # D-Bus system-wide daemon.
-  ++ optional config.services.dbus.enable
-    (import ../upstart-jobs/dbus.nix {
-      inherit (pkgs) stdenv dbus;
-      dbusServices =
-        # add config.services.dbus.services
-        pkgs.lib.optional config.services.hal.enable pkgs.hal ++
-        pkgs.lib.optional config.services.avahi.enable pkgs.avahi ++
-        pkgs.lib.optional config.services.disnix.enable pkgs.disnix
-        ;
-    })
-
   # Postfix mail server.
   ++ optional config.services.postfix.enable
     (import ../upstart-jobs/postfix.nix {
diff --git a/upstart-jobs/disnix.nix b/upstart-jobs/disnix.nix
index 1d387d93b6d..19ad3d0dcf9 100644
--- a/upstart-jobs/disnix.nix
+++ b/upstart-jobs/disnix.nix
@@ -30,6 +30,7 @@ in
 ###### implementation
 let
   cfg = config.services.disnix;
+  ifEnable = pkgs.lib.ifEnable cfg.enable;
 
   job = {
     name = "disnix";
@@ -53,10 +54,16 @@ in
 {
   require = [
     (import ../upstart-jobs/default.nix)
+    (import ../upstart-jobs/dbus.nix) # services.dbus.*
     options
   ];
 
   services = {
-    extraJobs = pkgs.lib.optional cfg.enable job;
+    extraJobs = ifEnable [job];
+
+    dbus = {
+      enable = cfg.enable;
+      services = ifEnable [pkgs.disnix];
+    };
   };
 }
diff --git a/upstart-jobs/hal.nix b/upstart-jobs/hal.nix
index b3f4e56f577..cd9d751d81a 100644
--- a/upstart-jobs/hal.nix
+++ b/upstart-jobs/hal.nix
@@ -66,7 +66,7 @@ in
     (import ../upstart-jobs/default.nix) # config.services.extraJobs
     # (import ../system/user.nix) # users.*
     # (import ../upstart-jobs/udev.nix) # services.udev.*
-    # (import ../upstart-jobs/dbus.nix) # services.dbus.*
+    (import ../upstart-jobs/dbus.nix) # services.dbus.*
     # (import ?) # config.environment.extraPackages
     options
   ];
@@ -89,7 +89,7 @@ in
 
     dbus = {
       enable = cfg.enable;
-      # services = ifEnable [hal];
+      services = ifEnable [hal];
     };
   };
 }