diff --git a/pkgs/development/libraries/dbus/default.nix b/pkgs/development/libraries/dbus/default.nix
index 1f1eff18959..fd7df4d5ba3 100644
--- a/pkgs/development/libraries/dbus/default.nix
+++ b/pkgs/development/libraries/dbus/default.nix
@@ -17,12 +17,6 @@
 , xmlto
 }:
 
-assert
-  x11Support ->
-    libX11 != null && libICE != null && libSM != null;
-
-assert enableSystemd -> systemd != null;
-
 stdenv.mkDerivation rec {
   pname = "dbus";
   version = "1.12.20";
diff --git a/pkgs/development/libraries/libusb1/default.nix b/pkgs/development/libraries/libusb1/default.nix
index 33cd34ea5a0..d69c8d670c4 100644
--- a/pkgs/development/libraries/libusb1/default.nix
+++ b/pkgs/development/libraries/libusb1/default.nix
@@ -3,14 +3,12 @@
 , autoreconfHook
 , pkg-config
 , enableUdev ? stdenv.isLinux && !stdenv.hostPlatform.isMusl
-, udev ? null
+, udev
 , libobjc
 , IOKit
 , withStatic ? false
 }:
 
-assert enableUdev -> udev != null;
-
 stdenv.mkDerivation rec {
   pname = "libusb";
   version = "1.0.24";
diff --git a/pkgs/misc/cups/default.nix b/pkgs/misc/cups/default.nix
index 0d740e071e1..3812ae500e5 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.