diff --git a/pkgs/applications/misc/kup/default.nix b/pkgs/applications/misc/kup/default.nix
deleted file mode 100644
index a956b7de416e..000000000000
--- a/pkgs/applications/misc/kup/default.nix
+++ /dev/null
@@ -1,63 +0,0 @@
-{
-  lib,
-  stdenv,
-  fetchFromGitLab,
-  extra-cmake-modules,
-  shared-mime-info,
-  wrapQtAppsHook,
-  kcoreaddons,
-  kdbusaddons,
-  ki18n,
-  kio,
-  solid,
-  kidletime,
-  knotifications,
-  kconfig,
-  kinit,
-  kjobwidgets,
-  kcmutils,
-  plasma-framework,
-  libgit2,
-}:
-
-stdenv.mkDerivation rec {
-  pname = "kup";
-  version = "0.10.0";
-
-  src = fetchFromGitLab {
-    domain = "invent.kde.org";
-    repo = "kup";
-    owner = "system";
-    rev = "kup-${version}";
-    hash = "sha256-G/GXmcQI1OBnCE7saPHeHDAMeL2WR6nVttMlKV2e01I=";
-  };
-
-  nativeBuildInputs = [
-    extra-cmake-modules
-    shared-mime-info
-    wrapQtAppsHook
-  ];
-
-  buildInputs = [
-    kcoreaddons
-    kdbusaddons
-    ki18n
-    kio
-    solid
-    kidletime
-    knotifications
-    kconfig
-    kinit
-    kjobwidgets
-    plasma-framework
-    libgit2
-    kcmutils
-  ];
-
-  meta = {
-    description = "Backup tool for KDE";
-    homepage = "https://apps.kde.org/kup";
-    license = lib.licenses.gpl2Plus;
-    maintainers = [ lib.maintainers.pwoelfel ];
-  };
-}
diff --git a/pkgs/top-level/aliases.nix b/pkgs/top-level/aliases.nix
index f18fb7aca085..68c4e8da6a77 100644
--- a/pkgs/top-level/aliases.nix
+++ b/pkgs/top-level/aliases.nix
@@ -1044,6 +1044,7 @@ mapAliases {
   kube3d = throw "'kube3d' has been renamed to/replaced by 'k3d'"; # Converted to throw 2025-10-27
   kubei = throw "'kubei' has been renamed to/replaced by 'kubeclarity'"; # Converted to throw 2025-10-27
   kubo-migrator-all-fs-repo-migrations = throw "'kubo-migrator-all-fs-repo-migrations' has been renamed to/replaced by 'kubo-fs-repo-migrations'"; # Converted to throw 2025-10-27
+  kup = throw "'kup' has been removed due to outdated KF5 dependencies. A Qt6 version is available at 'kdePackages.kup'."; # Added 2026-05-01
   kwm = throw "'kwm' has been removed since upstream is a 404"; # Added 2025-12-21
   ladspaH = warnAlias "'ladspaH' has been renamed to 'ladspa-header'" ladspa-header; # Added 2026-02-08
   languageMachines.frog = frog; # Added 2025-10-7
diff --git a/pkgs/top-level/all-packages.nix b/pkgs/top-level/all-packages.nix
index e659ff15c90c..f6afda8adbab 100644
--- a/pkgs/top-level/all-packages.nix
+++ b/pkgs/top-level/all-packages.nix
@@ -9705,8 +9705,6 @@ with pkgs;
     callPackage ../applications/networking/cluster/helm/plugins { }
   );
 
-  kup = libsForQt5.callPackage ../applications/misc/kup { };
-
   kvirc = libsForQt5.callPackage ../applications/networking/irc/kvirc { };
 
   ladspaPlugins = callPackage ../applications/audio/ladspa-plugins {