diff --git a/modules/services/x11/desktop-managers/kde4.nix b/modules/services/x11/desktop-managers/kde4.nix
index 6baa17be9a1..309def66f20 100644
--- a/modules/services/x11/desktop-managers/kde4.nix
+++ b/modules/services/x11/desktop-managers/kde4.nix
@@ -111,7 +111,7 @@ in
           pkgs.kde4.oxygen_icons
 
           # Starts KDE's Polkit authentication agent.
-          pkgs.polkit_kde_agent
+          pkgs.kde4.polkit_kde_agent
 
           # Phonon backends.
           pkgs.phonon_backend_gstreamer