diff --git a/modules/services/x11/display-managers/kdm.nix b/modules/services/x11/display-managers/kdm.nix
index 5264aa782289..349fd19adfe1 100644
--- a/modules/services/x11/display-managers/kdm.nix
+++ b/modules/services/x11/display-managers/kdm.nix
@@ -32,6 +32,12 @@ let
       [X-*-Greeter]
       HiddenUsers=root,nixbld1,nixbld2,nixbld3,nixbld4,nixbld5,nixbld6,nixbld7,nixbld8,nixbld9,nixbld10
       PluginsLogin=${kdebase_workspace}/lib/kde4/kgreet_classic.so
+      
+      ${optionalString (cfg.enableXDMCP)
+      ''
+        [Xdmcp]
+        Enable=true    
+      ''}
     '';
 
   kdmrc = pkgs.stdenv.mkDerivation {
@@ -61,6 +67,13 @@ in
         '';
       };
 
+      enableXDMCP = mkOption {
+        default = false;
+	description = ''
+	  Whether to enable XDMCP, which allows remote logins";
+	'';
+      };
+
       extraConfig = mkOption {
         default = "";
         description = ''