diff --git a/nixos/modules/hardware/printers.nix b/nixos/modules/hardware/printers.nix
index 5a348665ae10..059bf3024ddf 100644
--- a/nixos/modules/hardware/printers.nix
+++ b/nixos/modules/hardware/printers.nix
@@ -21,98 +21,12 @@ let
     submodule
     ;
 
-  ensurePrinter =
-    p:
-    let
-      args = lib.cli.toCommandLineShellGNU { } (
-        {
-          p = p.name;
-          v = p.deviceUri;
-          m = p.model;
-        }
-        // lib.optionalAttrs (p.location != null) {
-          L = p.location;
-        }
-        // lib.optionalAttrs (p.description != null) {
-          D = p.description;
-        }
-        // lib.optionalAttrs (p.ppdOptions != { }) {
-          o = lib.mapAttrsToList (name: value: "${name}=${value}") p.ppdOptions;
-        }
-      );
-    in
-    ''
-      # shellcheck disable=SC2016
-      ${pkgs.cups}/bin/lpadmin ${args} -E
-    '';
-
-  ensureDefaultPrinter = name: ''
-    ${pkgs.cups}/bin/lpadmin -d '${name}'
-  '';
-
   # "graph but not # or /" can't be implemented as regex alone due to missing lookahead support
   noInvalidChars = str: lib.all (c: c != "#" && c != "/") (lib.stringToCharacters str);
   printerName = (lib.types.addCheck (lib.types.strMatching "[[:graph:]]+") noInvalidChars) // {
     description = "printable string without spaces, # and /";
   };
 
-  getPrinters =
-    class:
-    lib.uniqueStrings (
-      lib.concatLists (
-        lib.textClosureList (lib.mapAttrs (
-          _:
-          {
-            classes ? [ ],
-            printers ? [ ],
-            ...
-          }:
-          {
-            deps = classes;
-            text = printers;
-          }
-        ) cfg.ensureClasses) [ class ]
-      )
-    );
-
-  mkClass = name: ''
-    lpadmin -p _tmp -v file:/dev/null
-    lpadmin -p _tmp -c ${escapeShellArg name}
-    lpadmin -x _tmp
-  '';
-
-  populateClass =
-    name:
-    {
-      description ? null,
-      location ? null,
-      ...
-    }:
-    lib.concatStringsSep "\n" [
-      (lib.optionalString (location != null) ''
-        lpadmin -p ${escapeShellArg name} -L ${escapeShellArg location}
-      '')
-
-      (lib.optionalString (description != null) ''
-        lpadmin -p ${escapeShellArg name} -D ${escapeShellArg description}
-      '')
-    ];
-
-  addPrintersToClass =
-    className: class:
-    let
-      printers = getPrinters className;
-      addToClass = printer: ''
-        lpadmin -p ${escapeShellArg printer} -c ${escapeShellArg className}
-      '';
-    in
-    map addToClass printers;
-
-  enableClass = className: ''
-    cupsenable ${escapeShellArg className}
-    cupsaccept ${escapeShellArg className}
-  '';
-
   # if CUPS is configured only to start when it's needed, we can kill the service
   # once the printer setup is done. However, if stateless is configured then we
   # can't shut down the servive without losing the printers (and classes) we
@@ -272,163 +186,248 @@ in
     };
   };
 
-  config.assertions = lib.mkIf config.services.printing.enable [
-    (
-      let
-        referencedClasses = lib.unique (
-          lib.flatten (
-            lib.mapAttrsToList (
-              _:
-              {
-                classes ? [ ],
-                ...
-              }:
-              classes
-            ) cfg.ensureClasses
-          )
-        );
-        definedClasses = lib.attrNames cfg.ensureClasses;
-        missingClasses = lib.subtractLists definedClasses referencedClasses;
-        getReferencingClasses =
-          missingClass:
-          (lib.mapAttrsToList (name: _: "`${name}`") (
-            lib.filterAttrs (
-              _:
-              {
-                classes ? [ ],
-                ...
-              }:
-              builtins.elem missingClass classes
-            ) cfg.ensureClasses
-          ));
-      in
-      {
-        assertion = missingClasses == [ ];
-        message = ''
-          One or more values of `config.hardware.printers.ensureClasses.<name>.classes`
-          contained values not present in `config.hardware.printers.ensureClasses`
+  config = lib.mkIf config.services.printing.enable {
+    assertions = [
+      (
+        let
+          referencedClasses = lib.unique (
+            lib.flatten (
+              lib.mapAttrsToList (
+                _:
+                {
+                  classes ? [ ],
+                  ...
+                }:
+                classes
+              ) cfg.ensureClasses
+            )
+          );
+          definedClasses = lib.attrNames cfg.ensureClasses;
+          missingClasses = lib.subtractLists definedClasses referencedClasses;
+          getReferencingClasses =
+            missingClass:
+            (lib.mapAttrsToList (name: _: "`${name}`") (
+              lib.filterAttrs (
+                _:
+                {
+                  classes ? [ ],
+                  ...
+                }:
+                builtins.elem missingClass classes
+              ) cfg.ensureClasses
+            ));
+        in
+        {
+          assertion = missingClasses == [ ];
+          message = ''
+            One or more values of `config.hardware.printers.ensureClasses.<name>.classes`
+            contained values not present in `config.hardware.printers.ensureClasses`
 
-          Missing classes:
-          ${lib.concatMapStringsSep "\n" (
-            p: "  - `${p}` (included in class(es): ${lib.concatStringsSep ", " (getReferencingClasses p)})"
-          ) missingClasses}
-        '';
-      }
-    )
-
-    (
-      let
-        referencedPrinters = lib.unique (
-          lib.flatten (
-            lib.mapAttrsToList (
-              _:
-              {
-                printers ? [ ],
-                ...
-              }:
-              printers
-            ) cfg.ensureClasses
-          )
-        );
-        definedPrinters = lib.catAttrs "name" cfg.ensurePrinters;
-        missingPrinters = lib.subtractLists definedPrinters referencedPrinters;
-        getReferencingClasses =
-          missingPrinter:
-          (lib.mapAttrsToList (name: _: "`${name}`") (
-            lib.filterAttrs (
-              _:
-              {
-                printers ? [ ],
-                ...
-              }:
-              builtins.elem missingPrinter printers
-            ) cfg.ensureClasses
-          ));
-      in
-      {
-        assertion = missingPrinters == [ ];
-        message = ''
-          One or more values of `config.hardware.printers.ensureClasses.<name>.printers`
-          contained values not present in `config.hardware.printers.ensurePrinters`
-
-          Missing printers:
-          ${lib.concatMapStringsSep "\n" (
-            p: "  - `${p}` (included in class(es): ${lib.concatStringsSep ", " (getReferencingClasses p)})"
-          ) missingPrinters}
-        '';
-      }
-    )
-  ];
-
-  config.systemd.services.ensure-printer-classes =
-    lib.mkIf (cfg.ensureClasses != { } && config.services.printing.enable)
-      {
-        description = "Ensure NixOS-configured CUPS classes";
-        wantedBy = [ "multi-user.target" ];
-        wants = [
-          "cups.service"
-        ];
-        after = [
-          "cups.service"
-          "ensure-printers.service"
-        ];
-        serviceConfig = {
-          Type = "oneshot";
-          RemainAfterExit = true;
-        };
-        path = with pkgs; [ cups ];
-        script =
-          let
-            attrMap = fn: l: map fn (builtins.attrNames l);
-            classDefs = lib.pipe cfg.ensureClasses [
-              (attrMap mkClass)
-              concatLines
-            ];
-            classAdds = lib.pipe cfg.ensureClasses [
-              (lib.mapAttrsToList addPrintersToClass)
-              lib.flatten
-              concatLines
-            ];
-            populatedClasses = lib.pipe cfg.ensureClasses [
-              (lib.mapAttrsToList populateClass)
-              concatLines
-            ];
-            enables = lib.pipe cfg.ensureClasses [
-              (attrMap enableClass)
-              concatLines
-            ];
-          in
-          ''
-            #### CLASS DEFINITIONS ####
-            ${classDefs}
-
-            #### ADDING PRINTERS TO CLASSES ####
-            ${classAdds}
-
-            #### POPULATING CLASSES ####
-            ${populatedClasses}
-
-            #### ENABLING CLASSES ####
-            ${enables}
-
-            ${lib.optionalString ultimatelyStopCups "systemctl stop cups.service"}
+            Missing classes:
+            ${lib.concatMapStringsSep "\n" (
+              p: "  - `${p}` (included in class(es): ${lib.concatStringsSep ", " (getReferencingClasses p)})"
+            ) missingClasses}
           '';
+        }
+      )
+
+      (
+        let
+          referencedPrinters = lib.unique (
+            lib.flatten (
+              lib.mapAttrsToList (
+                _:
+                {
+                  printers ? [ ],
+                  ...
+                }:
+                printers
+              ) cfg.ensureClasses
+            )
+          );
+          definedPrinters = lib.catAttrs "name" cfg.ensurePrinters;
+          missingPrinters = lib.subtractLists definedPrinters referencedPrinters;
+          getReferencingClasses =
+            missingPrinter:
+            (lib.mapAttrsToList (name: _: "`${name}`") (
+              lib.filterAttrs (
+                _:
+                {
+                  printers ? [ ],
+                  ...
+                }:
+                builtins.elem missingPrinter printers
+              ) cfg.ensureClasses
+            ));
+        in
+        {
+          assertion = missingPrinters == [ ];
+          message = ''
+            One or more values of `config.hardware.printers.ensureClasses.<name>.printers`
+            contained values not present in `config.hardware.printers.ensurePrinters`
+
+            Missing printers:
+            ${lib.concatMapStringsSep "\n" (
+              p: "  - `${p}` (included in class(es): ${lib.concatStringsSep ", " (getReferencingClasses p)})"
+            ) missingPrinters}
+          '';
+        }
+      )
+    ];
+
+    systemd.services.ensure-printer-classes = lib.mkIf (cfg.ensureClasses != { }) {
+      description = "Ensure NixOS-configured CUPS classes";
+      wantedBy = [ "multi-user.target" ];
+      wants = [
+        "cups.service"
+      ];
+      after = [
+        "cups.service"
+        "ensure-printers.service"
+      ];
+      serviceConfig = {
+        Type = "oneshot";
+        RemainAfterExit = true;
+      };
+      path = with pkgs; [ cups ];
+      script =
+        let
+          mkClass = name: ''
+            lpadmin -p _tmp -v file:/dev/null
+            lpadmin -p _tmp -c ${escapeShellArg name}
+            lpadmin -x _tmp
+          '';
+
+          populateClass =
+            name:
+            {
+              description ? null,
+              location ? null,
+              ...
+            }:
+            lib.concatStringsSep "\n" [
+              (lib.optionalString (location != null) ''
+                lpadmin -p ${escapeShellArg name} -L ${escapeShellArg location}
+              '')
+
+              (lib.optionalString (description != null) ''
+                lpadmin -p ${escapeShellArg name} -D ${escapeShellArg description}
+              '')
+            ];
+
+          getPrinters =
+            class:
+            lib.uniqueStrings (
+              lib.concatLists (
+                lib.textClosureList (lib.mapAttrs (
+                  _:
+                  {
+                    classes ? [ ],
+                    printers ? [ ],
+                    ...
+                  }:
+                  {
+                    deps = classes;
+                    text = printers;
+                  }
+                ) cfg.ensureClasses) [ class ]
+              )
+            );
+
+          addPrintersToClass =
+            className: class:
+            let
+              printers = getPrinters className;
+              addToClass = printer: ''
+                lpadmin -p ${escapeShellArg printer} -c ${escapeShellArg className}
+              '';
+            in
+            map addToClass printers;
+
+          enableClass = className: ''
+            cupsenable ${escapeShellArg className}
+            cupsaccept ${escapeShellArg className}
+          '';
+
+          attrMap = fn: l: map fn (builtins.attrNames l);
+          classDefs = lib.pipe cfg.ensureClasses [
+            (attrMap mkClass)
+            concatLines
+          ];
+          classAdds = lib.pipe cfg.ensureClasses [
+            (lib.mapAttrsToList addPrintersToClass)
+            lib.flatten
+            concatLines
+          ];
+          populatedClasses = lib.pipe cfg.ensureClasses [
+            (lib.mapAttrsToList populateClass)
+            concatLines
+          ];
+          enables = lib.pipe cfg.ensureClasses [
+            (attrMap enableClass)
+            concatLines
+          ];
+        in
+        ''
+          #### CLASS DEFINITIONS ####
+          ${classDefs}
+
+          #### ADDING PRINTERS TO CLASSES ####
+          ${classAdds}
+
+          #### POPULATING CLASSES ####
+          ${populatedClasses}
+
+          #### ENABLING CLASSES ####
+          ${enables}
+
+          ${lib.optionalString ultimatelyStopCups "systemctl stop cups.service"}
+        '';
+    };
+
+    systemd.services.ensure-printers = lib.mkIf (cfg.ensurePrinters != [ ]) {
+      description = "Ensure NixOS-configured CUPS printers";
+      wantedBy = [ "multi-user.target" ];
+      wants = [ "cups.service" ];
+      after = [ "cups.service" ];
+
+      serviceConfig = {
+        Type = "oneshot";
+        RemainAfterExit = true;
       };
 
-  config.systemd.services.ensure-printers =
-    lib.mkIf (cfg.ensurePrinters != [ ] && config.services.printing.enable)
-      {
-        description = "Ensure NixOS-configured CUPS printers";
-        wantedBy = [ "multi-user.target" ];
-        wants = [ "cups.service" ];
-        after = [ "cups.service" ];
+      script =
+        let
+          ensurePrinter =
+            p:
+            let
+              args = lib.cli.toCommandLineShellGNU { } (
+                {
+                  p = p.name;
+                  v = p.deviceUri;
+                  m = p.model;
+                }
+                // lib.optionalAttrs (p.location != null) {
+                  L = p.location;
+                }
+                // lib.optionalAttrs (p.description != null) {
+                  D = p.description;
+                }
+                // lib.optionalAttrs (p.ppdOptions != { }) {
+                  o = lib.mapAttrsToList (name: value: "${name}=${value}") p.ppdOptions;
+                }
+              );
+            in
+            ''
+              # shellcheck disable=SC2016
+              ${pkgs.cups}/bin/lpadmin ${args} -E
+            '';
 
-        serviceConfig = {
-          Type = "oneshot";
-          RemainAfterExit = true;
-        };
-
-        script = lib.concatStringsSep "\n" [
+          ensureDefaultPrinter = name: ''
+            ${pkgs.cups}/bin/lpadmin -d '${name}'
+          '';
+        in
+        lib.concatStringsSep "\n" [
           (lib.concatMapStrings ensurePrinter cfg.ensurePrinters)
           (lib.optionalString (cfg.ensureDefaultPrinter != null) (
             ensureDefaultPrinter cfg.ensureDefaultPrinter
@@ -439,5 +438,6 @@ in
             ultimatelyStopCups && !(config.systemd.services ? ensure-printer-classes)
           ) "systemctl stop cups.service")
         ];
-      };
+    };
+  };
 }