diff --git a/modules/misc/ids.nix b/modules/misc/ids.nix
index 2db841194e30..f8219c23068b 100644
--- a/modules/misc/ids.nix
+++ b/modules/misc/ids.nix
@@ -57,6 +57,7 @@ in
     cups = 36;
     foldingAtHome = 37;
     sabnzbd = 38;
+    kdm = 39;
     # When adding a uid, make sure it doesn't match an existing gid.
 
     nixbld = 30000; # start of range of uids
diff --git a/modules/services/x11/display-managers/kdm.nix b/modules/services/x11/display-managers/kdm.nix
index 1fa5b4f210ff..2c5a720f815e 100644
--- a/modules/services/x11/display-managers/kdm.nix
+++ b/modules/services/x11/display-managers/kdm.nix
@@ -106,6 +106,13 @@ in
 
     security.pam.services = [ { name = "kde"; } ];
       
+    users.extraUsers = singleton
+      { name = "kdm";
+        uid = config.ids.uids.kdm;
+        description = "kdm user";
+        home = "/tmp/kdm";
+      };
+
   };
   
 }