diff --git a/ChangeLog.md b/ChangeLog.md
index 6103b3b..2a046d4 100644
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -1,4 +1,24 @@
 
+# 2026-01-05
+
+ - Deprecated `mkSubmoduleOptions`. Declare options directly instead, e.g.
+   `options.flake.foo = mkOption { ... }`. This works since Nixpkgs 22.05.
+
+ - Deprecated `mkDeferredModuleType` and `mkDeferredModuleOption`. Use
+   `mkPerSystemType` and `mkPerSystemOption` respectively for `perSystem`
+   type-merging. For other uses, use Nixpkgs' `types.deferredModuleWith`.
+
+   Note: flake-parts' implementation returns a list on merge, whereas Nixpkgs'
+   returns a single module. Add `apply = m: [ m ];` to your option if you need
+   the list behavior.
+
+# 2024-05-16
+
+ - **Breaking**: Minimum supported Nixpkgs lib version is now 23.05 (was 22.05),
+   due to the use of the `class` argument in `evalModules`.
+
+ - Add `class` to `evalModules` calls for imports "type checking".
+
 # 2023-05-30
 
  - Fix a strictness issue in `perInput`, affecting `inputs'`, `self'`.
diff --git a/lib.nix b/lib.nix
index 09ee1e8..c8ea2ba 100644
--- a/lib.nix
+++ b/lib.nix
@@ -32,8 +32,22 @@ let
     then maybeFlake._type == "flake"
     else maybeFlake ? inputs && maybeFlake ? outputs && maybeFlake ? sourceInfo;
 
-  # Polyfill https://github.com/NixOS/nixpkgs/pull/163617
-  deferredModuleWith = lib.deferredModuleWith or (
+  /**
+    Deprecated for any use except type-merging into `perSystem`.
+    Use `lib.types.deferredModuleWith` instead, and add `apply = m: [ m ];` if needed.
+
+    The deferredModule type was pioneered in flake-parts for the `perSystem` option.
+    The Nixpkgs version has an improved merge function that returns a single module,
+    whereas this version returns a list. The flake-parts version was not updated to
+    match this improvement in Nixpkgs.
+
+    # History
+
+    This predates `lib.types.deferredModuleWith`, added in Nixpkgs 22.11
+    (https://github.com/NixOS/nixpkgs/pull/163617).
+    Documented as deprecated in flake-parts in January 2026.
+  */
+  deferredModuleWith =
     attrs@{ staticModules ? [ ] }: mkOptionType {
       name = "deferredModule";
       description = "module";
@@ -54,8 +68,14 @@ let
           staticModules = lhs.staticModules ++ rhs.staticModules;
         };
       };
-    }
-  );
+    };
+
+  # Internal: preserves legacy list-merge behavior for perSystem type-merging.
+  mkLegacyDeferredModuleType =
+    module:
+    deferredModuleWith {
+      staticModules = [ module ];
+    };
 
   errorExample = ''
     For example:
@@ -169,18 +189,32 @@ let
         };
       };
 
-    mkDeferredModuleType =
-      module:
-      deferredModuleWith {
-        staticModules = [ module ];
-      };
-    mkPerSystemType = mkDeferredModuleType;
+    /**
+      Deprecated. Use mkPerSystemType/mkPerSystemOption for `perSystem` type-merging, or
+      use Nixpkgs `types.deferredModule` directly, noting the lack of list wrapping;
+      see `deferredModuleWith` docs.
+    */
+    mkDeferredModuleType = mkLegacyDeferredModuleType;
 
+    /**
+      Given a module, construct an option type suitable for type-merging into `perSystem`'s type.
+    */
+    mkPerSystemType = mkLegacyDeferredModuleType;
+
+    /**
+      Deprecated. Use mkPerSystemOption for `perSystem` type-merging, or
+      use `mkOption` and Nixpkgs `types.deferredModule` directly, noting the
+      lack of list wrapping; see `deferredModuleWith` docs.
+    */
     mkDeferredModuleOption =
       module:
       mkOption {
         type = flake-parts-lib.mkPerSystemType module;
       };
+
+    /**
+      Given a module, construct an option declaration suitable for merging into the core `perSystem` module.
+    */
     mkPerSystemOption = mkDeferredModuleOption;
 
     # Polyfill https://github.com/NixOS/nixpkgs/pull/344216
@@ -268,7 +302,7 @@ let
 
   # A best effort, lenient estimate. Please use a recent nixpkgs lib if you
   # override it at all.
-  minVersion = "22.05";
+  minVersion = "23.05pre-git";
 
 in
 
diff --git a/modules/apps.nix b/modules/apps.nix
index 2f30a77..3030d32 100644
--- a/modules/apps.nix
+++ b/modules/apps.nix
@@ -8,12 +8,7 @@ let
     mkTransposedPerSystemModule
     ;
 
-  getExe = lib.getExe or (
-    x:
-    "${lib.getBin x}/bin/${x.meta.mainProgram or (throw ''Package ${x.name or ""} does not have meta.mainProgram set, so I don't know how to find the main executable. You can set meta.mainProgram, or pass the full path to executable, e.g. program = "''${pkg}/bin/foo"'')}"
-  );
-
-  programType = lib.types.coercedTo derivationType getExe lib.types.str;
+  programType = lib.types.coercedTo derivationType lib.getExe lib.types.str;
 
   derivationType = lib.types.package // {
     check = lib.isDerivation;
@@ -56,7 +51,7 @@ mkTransposedPerSystemModule {
     description = ''
       Programs runnable with nix run `<name>`.
     '';
-    example = lib.literalExpression or lib.literalExample ''
+    example = lib.literalExpression ''
       {
         default.program = "''${config.packages.hello}/bin/hello";
       }
diff --git a/modules/overlays.nix b/modules/overlays.nix
index 84285ff..172336c 100644
--- a/modules/overlays.nix
+++ b/modules/overlays.nix
@@ -14,7 +14,7 @@ in
       # This eta expansion exists for the sole purpose of making nix flake check happy.
       apply = lib.mapAttrs (_k: f: final: prev: f final prev);
       default = { };
-      example = lib.literalExpression or lib.literalExample ''
+      example = lib.literalExpression ''
         {
           default = final: prev: {};
         }