diff --git a/pkgs/misc/cups/default.nix b/pkgs/misc/cups/default.nix
index 0d740e071e11..3812ae500e5c 100644
--- a/pkgs/misc/cups/default.nix
+++ b/pkgs/misc/cups/default.nix
@@ -9,7 +9,7 @@
 , pam
 , dbus
 , enableSystemd ? stdenv.isLinux && !stdenv.hostPlatform.isMusl
-, systemd ? null
+, systemd
 , acl
 , gmp
 , darwin
@@ -20,8 +20,6 @@
 , coreutils
 }:
 
-assert enableSystemd -> systemd != null;
-
 ### IMPORTANT: before updating cups, make sure the nixos/tests/printing.nix test
 ### works at least for your platform.