diff --git a/nixos/modules/installer/cd-dvd/installation-cd-graphical-calamares-plasma6.nix b/nixos/modules/installer/cd-dvd/installation-cd-graphical-calamares-plasma6.nix
index d9fae053e771..90683fa088dc 100644
--- a/nixos/modules/installer/cd-dvd/installation-cd-graphical-calamares-plasma6.nix
+++ b/nixos/modules/installer/cd-dvd/installation-cd-graphical-calamares-plasma6.nix
@@ -31,6 +31,9 @@
     pkgs.kdePackages.plasma-workspace-wallpapers
   ];
 
+  # Avoid bundling an entire MariaDB installation on the ISO.
+  programs.kde-pim.enable = false;
+
   system.activationScripts.installerDesktop =
     let