diff --git a/pkgs/desktops/plasma-5/default.nix b/pkgs/desktops/plasma-5/default.nix
index 7e1bb2b1092..e5a23930888 100644
--- a/pkgs/desktops/plasma-5/default.nix
+++ b/pkgs/desktops/plasma-5/default.nix
@@ -24,9 +24,8 @@ existing packages here and modify it as necessary.
 
 */
 
-{
-  libsForQt5, lib, fetchurl,
-  gconf, gsettings-desktop-schemas
+{ libsForQt5, lib, config, fetchurl
+, gconf, gsettings-desktop-schemas
 }:
 
 let
@@ -123,7 +122,6 @@ let
       kscreen = callPackage ./kscreen.nix {};
       kscreenlocker = callPackage ./kscreenlocker.nix {};
       ksshaskpass = callPackage ./ksshaskpass.nix {};
-      ksysguard = throw "ksysguard has been replaced with plasma-systemmonitor";
       ksystemstats = callPackage ./ksystemstats.nix {};
       kwallet-pam = callPackage ./kwallet-pam.nix {};
       kwayland-integration = callPackage ./kwayland-integration.nix {};
@@ -164,6 +162,8 @@ let
         parachute = callPackage ./3rdparty/kwin/scripts/parachute.nix { };
       };
 
+    } // lib.optionalAttrs (config.allowAliases or true) {
+      ksysguard = throw "ksysguard has been replaced with plasma-systemmonitor";
     };
 in
 lib.makeScope libsForQt5.newScope packages
diff --git a/pkgs/top-level/qt5-packages.nix b/pkgs/top-level/qt5-packages.nix
index b98cbd08306..0c5cb662235 100644
--- a/pkgs/top-level/qt5-packages.nix
+++ b/pkgs/top-level/qt5-packages.nix
@@ -29,7 +29,7 @@ let
     mkPlasma5 = import ../desktops/plasma-5;
     attrs = {
       inherit libsForQt5;
-      inherit (pkgs) lib fetchurl;
+      inherit (pkgs) config lib fetchurl;
       gconf = pkgs.gnome2.GConf;
       inherit (pkgs) gsettings-desktop-schemas;
     };