diff --git a/nixos-modules/hardware/default.nix b/nixos-modules/hardware/default.nix
index 4439e3d..62b0ae6 100644
--- a/nixos-modules/hardware/default.nix
+++ b/nixos-modules/hardware/default.nix
@@ -30,30 +30,24 @@ in {
       usb_host_drv = cfg.usb.host.package;
     };
 
-    ahciConfig = with cfg.ahci;
-      lib.optionalString enable ''
-        , ahci_drv = Some ${
-          toDhall {
-            binary = ahciEris.cap;
-            atapi = atapiSupport;
-          }
-        }
-      '';
-
-    usbConfig = lib.optionalString cfg.usb.enable ''
-      , usb_block_drv = Some { binary = ${usbEris.usb_block_drv.cap} }
-      , usb_host_drv = Some ${
-        with cfg.usb.host;
-        toDhall {
-          binary = usbEris.usb_host_drv.cap;
-          bios_handoff = biosHandoff;
-          ehci = ehciSupport;
-          ohci = ohciSupport;
-          uhci = uhciSupport;
-          xhci = xhciSupport;
-        }
+    ahciConfig = lib.optionalString cfg.ahci.enable (with cfg.ahci; ''
+      , ahci_drv = Some {
+        , binary = ${ahciEris.cap}
+        , atapi = ${toDhall atapiSupport}
       }
-    '';
+    '');
+
+    usbConfig = lib.optionalString cfg.usb.enable (with cfg.usb.host; ''
+      , usb_block_drv = Some { binary = ${usbEris.usb_block_drv.cap} }
+      , usb_host_drv = Some {
+        , binary = ${usbEris.usb_host_drv.cap}
+        , bios_handoff = ${toDhall biosHandoff}
+        , ehci = ${toDhall ehciSupport}
+        , ohci = ${toDhall ohciSupport}
+        , uhci = ${toDhall uhciSupport}
+        , xhci = ${toDhall xhciSupport}
+        }
+    '');
 
     managerConfig = pkgs.writeText "device_manager.dhall" ''
       let Manager = ${pkgs.genodePackages.device_manager.dhall}/package.dhall