diff --git a/modules/services/x11/desktop-managers/kde4.nix b/modules/services/x11/desktop-managers/kde4.nix
index 2f7f62ce416..f4bf0d3f2c6 100644
--- a/modules/services/x11/desktop-managers/kde4.nix
+++ b/modules/services/x11/desktop-managers/kde4.nix
@@ -158,7 +158,7 @@ in
     services.udisks.enable = true;
     services.upower = mkIf config.powerManagement.enable { enable = true; };
 
-    security.pam.services = [ { name = "kde"; allowNullPassword = true; } ];
+    security.pam.services = [ { name = "kde"; allowNullPassword = true; startSession = true; } ];
 
   };