diff --git a/eslint.config.js b/eslint.config.js
index 60798d6f9c..1f5dce87a3 100644
--- a/eslint.config.js
+++ b/eslint.config.js
@@ -216,7 +216,7 @@ export default tsPlugin.config(
     name: "source/ez",
     files: ["express-zod-api/src/*.ts"],
     rules: {
-      complexity: ["error", 20],
+      complexity: ["error", 18],
       "allowed/dependencies": ["error", { packageDir: ezDir }],
       "no-restricted-syntax": [
         "warn",
diff --git a/express-zod-api/bench/experiment.bench.ts b/express-zod-api/bench/experiment.bench.ts
index e79364dc37..8d7ce7446d 100644
--- a/express-zod-api/bench/experiment.bench.ts
+++ b/express-zod-api/bench/experiment.bench.ts
@@ -1,14 +1,56 @@
-import * as R from "ramda";
 import { bench } from "vitest";
+import type { UploadedFile } from "express-fileupload";
+import { isObjectOfUploadShape } from "../src/upload-schema";
+import { z } from "zod";
 
-describe("Experiment for unique elements", () => {
-  const current = ["one", "two"];
+describe("Experiment for upload schema", () => {
+  const current = () =>
+    z.custom<UploadedFile>(
+      (subject) =>
+        typeof subject === "object" &&
+        subject !== null &&
+        "name" in subject &&
+        "encoding" in subject &&
+        "mimetype" in subject &&
+        "data" in subject &&
+        "tempFilePath" in subject &&
+        "truncated" in subject &&
+        "size" in subject &&
+        "md5" in subject &&
+        "mv" in subject &&
+        typeof subject.name === "string" &&
+        typeof subject.encoding === "string" &&
+        typeof subject.mimetype === "string" &&
+        Buffer.isBuffer(subject.data) &&
+        typeof subject.tempFilePath === "string" &&
+        typeof subject.truncated === "boolean" &&
+        typeof subject.size === "number" &&
+        typeof subject.md5 === "string" &&
+        typeof subject.mv === "function",
+    );
 
-  bench("set", () => {
-    return void [...new Set(current).add("null")];
+  const featured = () =>
+    z.custom<UploadedFile>(
+      (subject) =>
+        isObjectOfUploadShape(subject) &&
+        typeof subject.name === "string" &&
+        typeof subject.encoding === "string" &&
+        typeof subject.mimetype === "string" &&
+        Buffer.isBuffer(subject.data) &&
+        typeof subject.tempFilePath === "string" &&
+        typeof subject.truncated === "boolean" &&
+        typeof subject.size === "number" &&
+        typeof subject.md5 === "string" &&
+        typeof subject.mv === "function",
+    );
+
+  bench("current", () => {
+    const one = current();
+    one.safeParse({});
   });
 
-  bench("R.union", () => {
-    return void R.union(current, ["null"]);
+  bench("featured", () => {
+    const one = featured();
+    one.safeParse({});
   });
 });
diff --git a/express-zod-api/src/upload-schema.ts b/express-zod-api/src/upload-schema.ts
index e6aa2c906b..0943b8af17 100644
--- a/express-zod-api/src/upload-schema.ts
+++ b/express-zod-api/src/upload-schema.ts
@@ -1,23 +1,27 @@
 import type { UploadedFile } from "express-fileupload";
 import { z } from "zod";
+import { isObject } from "./common-helpers";
 
 export const ezUploadBrand = Symbol("Upload");
 
+/** @internal */
+export const isObjectOfUploadShape = (subject: unknown) =>
+  isObject(subject) &&
+  "name" in subject &&
+  "encoding" in subject &&
+  "mimetype" in subject &&
+  "data" in subject &&
+  "tempFilePath" in subject &&
+  "truncated" in subject &&
+  "size" in subject &&
+  "md5" in subject &&
+  "mv" in subject;
+
 export const upload = () =>
   z
     .custom<UploadedFile>(
       (subject) =>
-        typeof subject === "object" &&
-        subject !== null &&
-        "name" in subject &&
-        "encoding" in subject &&
-        "mimetype" in subject &&
-        "data" in subject &&
-        "tempFilePath" in subject &&
-        "truncated" in subject &&
-        "size" in subject &&
-        "md5" in subject &&
-        "mv" in subject &&
+        isObjectOfUploadShape(subject) &&
         typeof subject.name === "string" &&
         typeof subject.encoding === "string" &&
         typeof subject.mimetype === "string" &&
diff --git a/express-zod-api/tests/upload-schema.spec.ts b/express-zod-api/tests/upload-schema.spec.ts
index d6c4f671ad..f5c81a5d87 100644
--- a/express-zod-api/tests/upload-schema.spec.ts
+++ b/express-zod-api/tests/upload-schema.spec.ts
@@ -1,9 +1,60 @@
 import { z } from "zod";
 import { ez } from "../src";
 import { getBrand } from "@express-zod-api/zod-plugin";
-import { ezUploadBrand } from "../src/upload-schema";
+import { ezUploadBrand, isObjectOfUploadShape } from "../src/upload-schema";
 
 describe("ez.upload()", () => {
+  describe("isObjectOfUploadShape() helper", () => {
+    test.each([null, undefined, "test", 123, false])(
+      "should return false for non-object %#",
+      (subject) => {
+        expect(isObjectOfUploadShape(subject)).toBe(false);
+      },
+    );
+
+    test.each([
+      "name",
+      "encoding",
+      "mimetype",
+      "data",
+      "tempFilePath",
+      "truncated",
+      "size",
+      "md5",
+      "mv",
+    ] as const)("should return false when missing %s key", (key) => {
+      const input = {
+        name: null,
+        encoding: null,
+        mimetype: null,
+        data: null,
+        tempFilePath: null,
+        truncated: null,
+        size: null,
+        md5: null,
+        mv: null,
+      };
+      delete input[key];
+      expect(isObjectOfUploadShape(input)).toBe(false);
+    });
+
+    test("should return true for an object of valid shape", () => {
+      expect(
+        isObjectOfUploadShape({
+          name: null,
+          encoding: null,
+          mimetype: null,
+          data: null,
+          tempFilePath: null,
+          truncated: null,
+          size: null,
+          md5: null,
+          mv: null,
+        }),
+      ).toBe(true);
+    });
+  });
+
   describe("creation", () => {
     test("should create an instance", () => {
       const schema = ez.upload();