diff --git a/nixos/modules/services/web-servers/apache-httpd/default.nix b/nixos/modules/services/web-servers/apache-httpd/default.nix
index f6d5ac2fa55..e9cf9ae5e3e 100644
--- a/nixos/modules/services/web-servers/apache-httpd/default.nix
+++ b/nixos/modules/services/web-servers/apache-httpd/default.nix
@@ -30,7 +30,7 @@ let
 
     # Admin address: inherit from the main server if not specified for
     # a virtual host.
-    adminAddr = if cfg.adminAddr != "" then cfg.adminAddr else mainCfg.adminAddr;
+    adminAddr = if cfg.adminAddr != null then cfg.adminAddr else mainCfg.adminAddr;
 
     vhostConfig = cfg;
     serverConfig = mainCfg;
@@ -217,7 +217,7 @@ let
 
     ${concatMapStrings (alias: "ServerAlias ${alias}\n") cfg.serverAliases}
 
-    ${if cfg.sslServerCert != "" then ''
+    ${if cfg.sslServerCert != null then ''
       SSLCertificateFile ${cfg.sslServerCert}
       SSLCertificateKeyFile ${cfg.sslServerKey}
     '' else ""}
@@ -229,7 +229,7 @@ let
       SSLEngine off
     '' else ""}
 
-    ${if isMainServer || cfg.adminAddr != "" then ''
+    ${if isMainServer || cfg.adminAddr != null then ''
       ServerAdmin ${cfg.adminAddr}
     '' else ""}
 
@@ -260,7 +260,7 @@ let
 
     '' else ""}
 
-    ${if cfg.globalRedirect != "" then ''
+    ${if cfg.globalRedirect != null then ''
       RedirectPermanent / ${cfg.globalRedirect}
     '' else ""}
 
@@ -408,96 +408,104 @@ in
     services.httpd = {
 
       enable = mkOption {
+        type = types.bool;
         default = false;
-        description = "
-          Whether to enable the Apache httpd server.
-        ";
+        description = "Whether to enable the Apache HTTP Server.";
       };
 
       package = mkOption {
+        type = types.path;
         default = pkgs.apacheHttpd.override { mpm = mainCfg.multiProcessingModule; };
         example = "pkgs.apacheHttpd_2_4";
-        description = "
+        description = ''
           Overridable attribute of the Apache HTTP Server package to use.
-        ";
+        '';
       };
 
       configFile = mkOption {
+        type = types.path;
         default = confFile;
         example = literalExample ''pkgs.writeText "httpd.conf" "# my custom config file ...";'';
-        description = "
-          Overridable config file to use for Apache. By default, use the
-          file automatically generated by nixos.
-        ";
+        description = ''
+          Override the configuration file used by Apache. By default,
+          NixOS generates one automatically.
+        '';
       };
 
       extraConfig = mkOption {
+        type = types.lines;
         default = "";
-        description = "
-          These configuration lines will be appended to the Apache config
-          file. Note that this mechanism may not work when <option>configFile</option>
-          is overridden.
-        ";
+        description = ''
+          Cnfiguration lines appended to the generated Apache
+          configuration file. Note that this mechanism may not work
+          when <option>configFile</option> is overridden.
+        '';
       };
 
       extraModules = mkOption {
+        type = types.listOf types.unspecified;
         default = [];
         example = [ "proxy_connect" { name = "php5"; path = "${php}/modules/libphp5.so"; } ];
         description = ''
-          Specifies additional Apache modules.  These can be specified
-          as a string in the case of modules distributed with Apache,
-          or as an attribute set specifying the
+          Additional Apache modules to be used.  These can be
+          specified as a string in the case of modules distributed
+          with Apache, or as an attribute set specifying the
           <varname>name</varname> and <varname>path</varname> of the
           module.
         '';
       };
 
       logPerVirtualHost = mkOption {
+        type = types.bool;
         default = false;
-        description = "
+        description = ''
           If enabled, each virtual host gets its own
           <filename>access_log</filename> and
           <filename>error_log</filename>, namely suffixed by the
           <option>hostName</option> of the virtual host.
-        ";
+        '';
       };
 
       user = mkOption {
+        type = types.str;
         default = "wwwrun";
-        description = "
+        description = ''
           User account under which httpd runs.  The account is created
           automatically if it doesn't exist.
-        ";
+        '';
       };
 
       group = mkOption {
+        type = types.str;
         default = "wwwrun";
-        description = "
+        description = ''
           Group under which httpd runs.  The account is created
           automatically if it doesn't exist.
-        ";
+        '';
       };
 
       logDir = mkOption {
+        type = types.path;
         default = "/var/log/httpd";
-        description = "
+        description = ''
           Directory for Apache's log files.  It is created automatically.
-        ";
+        '';
       };
 
       stateDir = mkOption {
-        default = "/var/run/httpd";
-        description = "
+        type = types.path;
+        default = "/run/httpd";
+        description = ''
           Directory for Apache's transient runtime state (such as PID
           files).  It is created automatically.  Note that the default,
-          <filename>/var/run/httpd</filename>, is deleted at boot time.
-        ";
+          <filename>/run/httpd</filename>, is deleted at boot time.
+        '';
       };
 
       virtualHosts = mkOption {
         type = types.listOf (types.submodule (
           { options = import ./per-server-options.nix {
-              inherit mkOption;
+              inherit pkgs;
               forMainServer = false;
             };
           }));
@@ -519,6 +527,7 @@ in
       };
 
       phpOptions = mkOption {
+        type = types.lines;
         default = "";
         example =
           ''
@@ -529,9 +538,9 @@ in
       };
 
       multiProcessingModule = mkOption {
+        type = types.str;
         default = "prefork";
         example = "worker";
-        type = types.uniq types.string;
         description =
           ''
             Multi-processing module to be used by Apache.  Available
@@ -546,12 +555,14 @@ in
       };
 
       maxClients = mkOption {
+        type = types.int;
         default = 150;
         example = 8;
         description = "Maximum number of httpd processes (prefork)";
       };
 
       maxRequestsPerChild = mkOption {
+        type = types.int;
         default = 0;
         example = 500;
         description =
@@ -561,7 +572,7 @@ in
 
     # Include the options shared between the main server and virtual hosts.
     // (import ./per-server-options.nix {
-      inherit mkOption;
+      inherit pkgs;
       forMainServer = true;
     });
 
diff --git a/nixos/modules/services/web-servers/apache-httpd/per-server-options.nix b/nixos/modules/services/web-servers/apache-httpd/per-server-options.nix
index a5227bae2d4..53f34e28c27 100644
--- a/nixos/modules/services/web-servers/apache-httpd/per-server-options.nix
+++ b/nixos/modules/services/web-servers/apache-httpd/per-server-options.nix
@@ -3,38 +3,40 @@
 # has additional options that affect the web server as a whole, like
 # the user/group to run under.)
 
-{forMainServer, mkOption}:
+{ forMainServer, pkgs }:
+
+with pkgs.lib;
 
 {
 
   hostName = mkOption {
+    type = types.str;
     default = "localhost";
-    description = "
-      Canonical hostname for the server.
-    ";
+    description = "Canonical hostname for the server.";
   };
 
   serverAliases = mkOption {
+    type = types.listOf types.str;
     default = [];
     example = ["www.example.org" "www.example.org:8080" "example.org"];
-    description = "
+    description = ''
       Additional names of virtual hosts served by this virtual host configuration.
-    ";
+    '';
   };
 
   port = mkOption {
+    type = types.int;
     default = 0;
-    description = "
+    description = ''
       Port for the server.  0 means use the default port: 80 for http
       and 443 for https (i.e. when enableSSL is set).
-    ";
+    '';
   };
 
   enableSSL = mkOption {
+    type = types.bool;
     default = false;
-    description = "
-      Whether to enable SSL (https) support.
-    ";
+    description = "Whether to enable SSL (https) support.";
   };
 
   # Note: sslServerCert and sslServerKey can be left empty, but this
@@ -42,62 +44,62 @@
   # main server).
 
   sslServerCert = mkOption {
-    default = "";
+    type = types.nullOr types.path;
+    default = null;
     example = "/var/host.cert";
-    description = "
-      Path to server SSL certificate.
-    ";
+    description = "Path to server SSL certificate.";
   };
 
   sslServerKey = mkOption {
-    default = "";
+    type = types.path;
     example = "/var/host.key";
-    description = "
-      Path to server SSL certificate key.
-    ";
+    description = "Path to server SSL certificate key.";
   };
 
   adminAddr = mkOption ({
+    type = types.nullOr types.str;
     example = "admin@example.org";
-    description = "
-      E-mail address of the server administrator.
-    ";
-  } // (if forMainServer then {} else {default = "";}));
+    description = "E-mail address of the server administrator.";
+  } // (if forMainServer then {} else {default = null;}));
 
   documentRoot = mkOption {
+    type = types.nullOr types.path;
     default = null;
     example = "/data/webserver/docs";
-    description = "
+    description = ''
       The path of Apache's document root directory.  If left undefined,
       an empty directory in the Nix store will be used as root.
-    ";
+    '';
   };
 
   servedDirs = mkOption {
+    type = types.listOf types.attrs;
     default = [];
     example = [
       { urlPath = "/nix";
         dir = "/home/eelco/Dev/nix-homepage";
       }
     ];
-    description = "
+    description = ''
       This option provides a simple way to serve static directories.
-    ";
+    '';
   };
 
   servedFiles = mkOption {
+    type = types.listOf types.attrs;
     default = [];
     example = [
       { urlPath = "/foo/bar.png";
         dir = "/home/eelco/some-file.png";
       }
     ];
-    description = "
+    description = ''
       This option provides a simple way to serve individual, static files.
-    ";
+    '';
   };
 
   extraConfig = mkOption {
+    type = types.lines;
     default = "";
     example = ''
       <Directory /home>
@@ -105,37 +107,39 @@
         AllowOverride All
       </Directory>
     '';
-    description = "
+    description = ''
       These lines go to httpd.conf verbatim. They will go after
       directories and directory aliases defined by default.
-    ";
+    '';
   };
 
   extraSubservices = mkOption {
+    type = types.listOf types.unspecified;
     default = [];
-    description = "
-      Extra subservices to enable in the webserver.
-    ";
+    description = "Extra subservices to enable in the webserver.";
   };
 
   enableUserDir = mkOption {
+    type = types.bool;
     default = false;
-    description = "
+    description = ''
       Whether to enable serving <filename>~/public_html</filename> as
       <literal>/~<replaceable>username</replaceable></literal>.
-    ";
+    '';
   };
 
   globalRedirect = mkOption {
-    default = "";
+    type = types.nullOr types.str;
+    default = null;
     example = http://newserver.example.org/;
-    description = "
+    description = ''
       If set, all requests for this host are redirected permanently to
       the given URL.
-    ";
+    '';
   };
 
   logFormat = mkOption {
+    type = types.str;
     default = "common";
     example = "combined";
     description = "