diff --git a/.vscode/settings.json b/.vscode/settings.json
index eadb428d..5b821aee 100644
--- a/.vscode/settings.json
+++ b/.vscode/settings.json
@@ -2,7 +2,9 @@
   "eslint.run": "onSave",
   "editor.formatOnSave": true,
   "editor.defaultFormatter": "esbenp.prettier-vscode",
-  "editor.codeActionsOnSave": { "source.fixAll.eslint": true },
+  "editor.codeActionsOnSave": {
+    "source.fixAll.eslint": "explicit"
+  },
   "typescript.tsdk": "node_modules/typescript/lib",
   "typescript.referencesCodeLens.enabled": true,
   "files.eol": "\n",
diff --git a/package-lock.json b/package-lock.json
index 1d001bd2..4a604e8f 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -43,7 +43,7 @@
         "ts-jest": "^29.1.1",
         "ts-node": "^10.9.1",
         "typescript": "^5.1.6",
-        "zod": "^3.21.4"
+        "zod": "^3.22.4"
       }
     },
     "node_modules/@aashutoshrathi/word-wrap": {
@@ -7584,9 +7584,9 @@
       }
     },
     "node_modules/zod": {
-      "version": "3.21.4",
-      "resolved": "https://registry.npmjs.org/zod/-/zod-3.21.4.tgz",
-      "integrity": "sha512-m46AKbrzKVzOzs/DZgVnG5H55N1sv1M8qZU3A8RIKbs3mrACDNeIOeilDymVb2HdmP8uwshOCF4uJ8uM9rCqJw==",
+      "version": "3.22.4",
+      "resolved": "https://registry.npmjs.org/zod/-/zod-3.22.4.tgz",
+      "integrity": "sha512-iC+8Io04lddc+mVqQ9AZ7OQ2MrUKGN+oIQyq1vemgt46jwCwLfhq7/pwnBnNXXXZb8VTVLKwp9EDkx+ryxIWmg==",
       "dev": true,
       "funding": {
         "url": "https://github.com/sponsors/colinhacks"
diff --git a/package.json b/package.json
index f9231ec3..f2d5fdd3 100644
--- a/package.json
+++ b/package.json
@@ -106,6 +106,6 @@
     "ts-jest": "^29.1.1",
     "ts-node": "^10.9.1",
     "typescript": "^5.1.6",
-    "zod": "^3.21.4"
+    "zod": "^3.22.4"
   }
 }
diff --git a/servers/all/$server.ts b/servers/all/$server.ts
index 137071b8..9f950b7a 100644
--- a/servers/all/$server.ts
+++ b/servers/all/$server.ts
@@ -350,7 +350,7 @@ export default (fastify: FastifyInstance, options: FrourioOptions = {}) => {
       preParsing: hooks_gx3glp.preParsing,
       preValidation: formatMultipartData([['requiredArr', false], ['optionalArr', true], ['empty', true], ['vals', false], ['files', false]]),
     },
-    methodToHandler(controller_17nfdm3.post.handler),
+    asyncMethodToHandler(controller_17nfdm3.post.handler),
   );
 
   fastify.get(
diff --git a/servers/all/api/$relay.ts b/servers/all/api/$relay.ts
index 1cfe169b..686fd3dc 100644
--- a/servers/all/api/$relay.ts
+++ b/servers/all/api/$relay.ts
@@ -24,13 +24,15 @@ export function defineController<M extends ServerMethods, T extends Record<strin
 }
 
 export const multipartFileValidator = (): z.ZodType<MultipartFile> =>
-  z.object({
-    type: z.literal('file'),
-    toBuffer: z.function().returns(z.promise(z.instanceof(Buffer))),
-    file: z.instanceof(Readable).and(z.object({ truncated: z.boolean(), bytesRead: z.number() })),
-    fieldname: z.string(),
-    filename: z.string(),
-    encoding: z.string(),
-    mimetype: z.string(),
-    fields: z.record(z.any()),
-  });
+  z
+    .object({
+      type: z.literal('file'),
+      toBuffer: z.function().returns(z.any()),
+      file: z.instanceof(Readable).and(z.object({ truncated: z.boolean(), bytesRead: z.number() }).passthrough()),
+      fieldname: z.string(),
+      filename: z.string(),
+      encoding: z.string(),
+      mimetype: z.string(),
+      fields: z.record(z.any()),
+    })
+    .passthrough();
diff --git a/servers/all/api/500/$relay.ts b/servers/all/api/500/$relay.ts
index fec711cc..e7301674 100644
--- a/servers/all/api/500/$relay.ts
+++ b/servers/all/api/500/$relay.ts
@@ -24,13 +24,15 @@ export function defineController<M extends ServerMethods, T extends Record<strin
 }
 
 export const multipartFileValidator = (): z.ZodType<MultipartFile> =>
-  z.object({
-    type: z.literal('file'),
-    toBuffer: z.function().returns(z.promise(z.instanceof(Buffer))),
-    file: z.instanceof(Readable).and(z.object({ truncated: z.boolean(), bytesRead: z.number() })),
-    fieldname: z.string(),
-    filename: z.string(),
-    encoding: z.string(),
-    mimetype: z.string(),
-    fields: z.record(z.any()),
-  });
+  z
+    .object({
+      type: z.literal('file'),
+      toBuffer: z.function().returns(z.any()),
+      file: z.instanceof(Readable).and(z.object({ truncated: z.boolean(), bytesRead: z.number() }).passthrough()),
+      fieldname: z.string(),
+      filename: z.string(),
+      encoding: z.string(),
+      mimetype: z.string(),
+      fields: z.record(z.any()),
+    })
+    .passthrough();
diff --git a/servers/all/api/empty/$relay.ts b/servers/all/api/empty/$relay.ts
index fec711cc..e7301674 100644
--- a/servers/all/api/empty/$relay.ts
+++ b/servers/all/api/empty/$relay.ts
@@ -24,13 +24,15 @@ export function defineController<M extends ServerMethods, T extends Record<strin
 }
 
 export const multipartFileValidator = (): z.ZodType<MultipartFile> =>
-  z.object({
-    type: z.literal('file'),
-    toBuffer: z.function().returns(z.promise(z.instanceof(Buffer))),
-    file: z.instanceof(Readable).and(z.object({ truncated: z.boolean(), bytesRead: z.number() })),
-    fieldname: z.string(),
-    filename: z.string(),
-    encoding: z.string(),
-    mimetype: z.string(),
-    fields: z.record(z.any()),
-  });
+  z
+    .object({
+      type: z.literal('file'),
+      toBuffer: z.function().returns(z.any()),
+      file: z.instanceof(Readable).and(z.object({ truncated: z.boolean(), bytesRead: z.number() }).passthrough()),
+      fieldname: z.string(),
+      filename: z.string(),
+      encoding: z.string(),
+      mimetype: z.string(),
+      fields: z.record(z.any()),
+    })
+    .passthrough();
diff --git a/servers/all/api/empty/noEmpty/$relay.ts b/servers/all/api/empty/noEmpty/$relay.ts
index 1dd6e479..3bb599b1 100644
--- a/servers/all/api/empty/noEmpty/$relay.ts
+++ b/servers/all/api/empty/noEmpty/$relay.ts
@@ -24,13 +24,15 @@ export function defineController<M extends ServerMethods, T extends Record<strin
 }
 
 export const multipartFileValidator = (): z.ZodType<MultipartFile> =>
-  z.object({
-    type: z.literal('file'),
-    toBuffer: z.function().returns(z.promise(z.instanceof(Buffer))),
-    file: z.instanceof(Readable).and(z.object({ truncated: z.boolean(), bytesRead: z.number() })),
-    fieldname: z.string(),
-    filename: z.string(),
-    encoding: z.string(),
-    mimetype: z.string(),
-    fields: z.record(z.any()),
-  });
+  z
+    .object({
+      type: z.literal('file'),
+      toBuffer: z.function().returns(z.any()),
+      file: z.instanceof(Readable).and(z.object({ truncated: z.boolean(), bytesRead: z.number() }).passthrough()),
+      fieldname: z.string(),
+      filename: z.string(),
+      encoding: z.string(),
+      mimetype: z.string(),
+      fields: z.record(z.any()),
+    })
+    .passthrough();
diff --git a/servers/all/api/multiForm/$relay.ts b/servers/all/api/multiForm/$relay.ts
index fec711cc..e7301674 100644
--- a/servers/all/api/multiForm/$relay.ts
+++ b/servers/all/api/multiForm/$relay.ts
@@ -24,13 +24,15 @@ export function defineController<M extends ServerMethods, T extends Record<strin
 }
 
 export const multipartFileValidator = (): z.ZodType<MultipartFile> =>
-  z.object({
-    type: z.literal('file'),
-    toBuffer: z.function().returns(z.promise(z.instanceof(Buffer))),
-    file: z.instanceof(Readable).and(z.object({ truncated: z.boolean(), bytesRead: z.number() })),
-    fieldname: z.string(),
-    filename: z.string(),
-    encoding: z.string(),
-    mimetype: z.string(),
-    fields: z.record(z.any()),
-  });
+  z
+    .object({
+      type: z.literal('file'),
+      toBuffer: z.function().returns(z.any()),
+      file: z.instanceof(Readable).and(z.object({ truncated: z.boolean(), bytesRead: z.number() }).passthrough()),
+      fieldname: z.string(),
+      filename: z.string(),
+      encoding: z.string(),
+      mimetype: z.string(),
+      fields: z.record(z.any()),
+    })
+    .passthrough();
diff --git a/servers/all/api/multiForm/controller.ts b/servers/all/api/multiForm/controller.ts
index 5f0349b9..c1777644 100644
--- a/servers/all/api/multiForm/controller.ts
+++ b/servers/all/api/multiForm/controller.ts
@@ -15,12 +15,18 @@ export default defineController(() => ({
         files: z.array(multipartFileValidator()),
       }),
     },
-    handler: ({ body }) => ({
-      status: 201,
-      body: Object.entries(body).reduce(
-        (p, [key, val]) => ({ ...p, [key]: Array.isArray(val) ? val.length : -1 }),
-        {} as Methods['post']['resBody']
-      ),
-    }),
+    handler: async ({ body }) => {
+      const res = {
+        status: 201 as const,
+        body: Object.entries(body).reduce(
+          (p, [key, val]) => ({ ...p, [key]: Array.isArray(val) ? val.length : -1 }),
+          {} as Methods['post']['resBody']
+        ),
+      };
+
+      await body.icon.toBuffer(); // for validator test
+
+      return res;
+    },
   },
 }));
diff --git a/servers/all/api/texts/$relay.ts b/servers/all/api/texts/$relay.ts
index fec711cc..e7301674 100644
--- a/servers/all/api/texts/$relay.ts
+++ b/servers/all/api/texts/$relay.ts
@@ -24,13 +24,15 @@ export function defineController<M extends ServerMethods, T extends Record<strin
 }
 
 export const multipartFileValidator = (): z.ZodType<MultipartFile> =>
-  z.object({
-    type: z.literal('file'),
-    toBuffer: z.function().returns(z.promise(z.instanceof(Buffer))),
-    file: z.instanceof(Readable).and(z.object({ truncated: z.boolean(), bytesRead: z.number() })),
-    fieldname: z.string(),
-    filename: z.string(),
-    encoding: z.string(),
-    mimetype: z.string(),
-    fields: z.record(z.any()),
-  });
+  z
+    .object({
+      type: z.literal('file'),
+      toBuffer: z.function().returns(z.any()),
+      file: z.instanceof(Readable).and(z.object({ truncated: z.boolean(), bytesRead: z.number() }).passthrough()),
+      fieldname: z.string(),
+      filename: z.string(),
+      encoding: z.string(),
+      mimetype: z.string(),
+      fields: z.record(z.any()),
+    })
+    .passthrough();
diff --git a/servers/all/api/texts/_label@string/$relay.ts b/servers/all/api/texts/_label@string/$relay.ts
index 5b9a5024..843a7a55 100644
--- a/servers/all/api/texts/_label@string/$relay.ts
+++ b/servers/all/api/texts/_label@string/$relay.ts
@@ -34,13 +34,15 @@ export function defineController<M extends ServerMethods, T extends Record<strin
 }
 
 export const multipartFileValidator = (): z.ZodType<MultipartFile> =>
-  z.object({
-    type: z.literal('file'),
-    toBuffer: z.function().returns(z.promise(z.instanceof(Buffer))),
-    file: z.instanceof(Readable).and(z.object({ truncated: z.boolean(), bytesRead: z.number() })),
-    fieldname: z.string(),
-    filename: z.string(),
-    encoding: z.string(),
-    mimetype: z.string(),
-    fields: z.record(z.any()),
-  });
+  z
+    .object({
+      type: z.literal('file'),
+      toBuffer: z.function().returns(z.any()),
+      file: z.instanceof(Readable).and(z.object({ truncated: z.boolean(), bytesRead: z.number() }).passthrough()),
+      fieldname: z.string(),
+      filename: z.string(),
+      encoding: z.string(),
+      mimetype: z.string(),
+      fields: z.record(z.any()),
+    })
+    .passthrough();
diff --git a/servers/all/api/texts/sample/$relay.ts b/servers/all/api/texts/sample/$relay.ts
index 1dd6e479..3bb599b1 100644
--- a/servers/all/api/texts/sample/$relay.ts
+++ b/servers/all/api/texts/sample/$relay.ts
@@ -24,13 +24,15 @@ export function defineController<M extends ServerMethods, T extends Record<strin
 }
 
 export const multipartFileValidator = (): z.ZodType<MultipartFile> =>
-  z.object({
-    type: z.literal('file'),
-    toBuffer: z.function().returns(z.promise(z.instanceof(Buffer))),
-    file: z.instanceof(Readable).and(z.object({ truncated: z.boolean(), bytesRead: z.number() })),
-    fieldname: z.string(),
-    filename: z.string(),
-    encoding: z.string(),
-    mimetype: z.string(),
-    fields: z.record(z.any()),
-  });
+  z
+    .object({
+      type: z.literal('file'),
+      toBuffer: z.function().returns(z.any()),
+      file: z.instanceof(Readable).and(z.object({ truncated: z.boolean(), bytesRead: z.number() }).passthrough()),
+      fieldname: z.string(),
+      filename: z.string(),
+      encoding: z.string(),
+      mimetype: z.string(),
+      fields: z.record(z.any()),
+    })
+    .passthrough();
diff --git a/servers/all/api/users/$relay.ts b/servers/all/api/users/$relay.ts
index 0c49c45b..52b94b5e 100644
--- a/servers/all/api/users/$relay.ts
+++ b/servers/all/api/users/$relay.ts
@@ -28,13 +28,15 @@ export function defineController<M extends ServerMethods, T extends Record<strin
 }
 
 export const multipartFileValidator = (): z.ZodType<MultipartFile> =>
-  z.object({
-    type: z.literal('file'),
-    toBuffer: z.function().returns(z.promise(z.instanceof(Buffer))),
-    file: z.instanceof(Readable).and(z.object({ truncated: z.boolean(), bytesRead: z.number() })),
-    fieldname: z.string(),
-    filename: z.string(),
-    encoding: z.string(),
-    mimetype: z.string(),
-    fields: z.record(z.any()),
-  });
+  z
+    .object({
+      type: z.literal('file'),
+      toBuffer: z.function().returns(z.any()),
+      file: z.instanceof(Readable).and(z.object({ truncated: z.boolean(), bytesRead: z.number() }).passthrough()),
+      fieldname: z.string(),
+      filename: z.string(),
+      encoding: z.string(),
+      mimetype: z.string(),
+      fields: z.record(z.any()),
+    })
+    .passthrough();
diff --git a/servers/all/api/users/_userId@number/$relay.ts b/servers/all/api/users/_userId@number/$relay.ts
index 5362aea4..5812078f 100644
--- a/servers/all/api/users/_userId@number/$relay.ts
+++ b/servers/all/api/users/_userId@number/$relay.ts
@@ -38,13 +38,15 @@ export function defineController<M extends ServerMethods, T extends Record<strin
 }
 
 export const multipartFileValidator = (): z.ZodType<MultipartFile> =>
-  z.object({
-    type: z.literal('file'),
-    toBuffer: z.function().returns(z.promise(z.instanceof(Buffer))),
-    file: z.instanceof(Readable).and(z.object({ truncated: z.boolean(), bytesRead: z.number() })),
-    fieldname: z.string(),
-    filename: z.string(),
-    encoding: z.string(),
-    mimetype: z.string(),
-    fields: z.record(z.any()),
-  });
+  z
+    .object({
+      type: z.literal('file'),
+      toBuffer: z.function().returns(z.any()),
+      file: z.instanceof(Readable).and(z.object({ truncated: z.boolean(), bytesRead: z.number() }).passthrough()),
+      fieldname: z.string(),
+      filename: z.string(),
+      encoding: z.string(),
+      mimetype: z.string(),
+      fields: z.record(z.any()),
+    })
+    .passthrough();
diff --git a/servers/all/api/users/_userId@number/_name/$relay.ts b/servers/all/api/users/_userId@number/_name/$relay.ts
index 5741a44b..34296d89 100644
--- a/servers/all/api/users/_userId@number/_name/$relay.ts
+++ b/servers/all/api/users/_userId@number/_name/$relay.ts
@@ -39,13 +39,15 @@ export function defineController<M extends ServerMethods, T extends Record<strin
 }
 
 export const multipartFileValidator = (): z.ZodType<MultipartFile> =>
-  z.object({
-    type: z.literal('file'),
-    toBuffer: z.function().returns(z.promise(z.instanceof(Buffer))),
-    file: z.instanceof(Readable).and(z.object({ truncated: z.boolean(), bytesRead: z.number() })),
-    fieldname: z.string(),
-    filename: z.string(),
-    encoding: z.string(),
-    mimetype: z.string(),
-    fields: z.record(z.any()),
-  });
+  z
+    .object({
+      type: z.literal('file'),
+      toBuffer: z.function().returns(z.any()),
+      file: z.instanceof(Readable).and(z.object({ truncated: z.boolean(), bytesRead: z.number() }).passthrough()),
+      fieldname: z.string(),
+      filename: z.string(),
+      encoding: z.string(),
+      mimetype: z.string(),
+      fields: z.record(z.any()),
+    })
+    .passthrough();
diff --git a/servers/all/api/zod/$relay.ts b/servers/all/api/zod/$relay.ts
index fec711cc..e7301674 100644
--- a/servers/all/api/zod/$relay.ts
+++ b/servers/all/api/zod/$relay.ts
@@ -24,13 +24,15 @@ export function defineController<M extends ServerMethods, T extends Record<strin
 }
 
 export const multipartFileValidator = (): z.ZodType<MultipartFile> =>
-  z.object({
-    type: z.literal('file'),
-    toBuffer: z.function().returns(z.promise(z.instanceof(Buffer))),
-    file: z.instanceof(Readable).and(z.object({ truncated: z.boolean(), bytesRead: z.number() })),
-    fieldname: z.string(),
-    filename: z.string(),
-    encoding: z.string(),
-    mimetype: z.string(),
-    fields: z.record(z.any()),
-  });
+  z
+    .object({
+      type: z.literal('file'),
+      toBuffer: z.function().returns(z.any()),
+      file: z.instanceof(Readable).and(z.object({ truncated: z.boolean(), bytesRead: z.number() }).passthrough()),
+      fieldname: z.string(),
+      filename: z.string(),
+      encoding: z.string(),
+      mimetype: z.string(),
+      fields: z.record(z.any()),
+    })
+    .passthrough();
diff --git a/servers/minimum/api/$relay.ts b/servers/minimum/api/$relay.ts
index 1cfe169b..686fd3dc 100644
--- a/servers/minimum/api/$relay.ts
+++ b/servers/minimum/api/$relay.ts
@@ -24,13 +24,15 @@ export function defineController<M extends ServerMethods, T extends Record<strin
 }
 
 export const multipartFileValidator = (): z.ZodType<MultipartFile> =>
-  z.object({
-    type: z.literal('file'),
-    toBuffer: z.function().returns(z.promise(z.instanceof(Buffer))),
-    file: z.instanceof(Readable).and(z.object({ truncated: z.boolean(), bytesRead: z.number() })),
-    fieldname: z.string(),
-    filename: z.string(),
-    encoding: z.string(),
-    mimetype: z.string(),
-    fields: z.record(z.any()),
-  });
+  z
+    .object({
+      type: z.literal('file'),
+      toBuffer: z.function().returns(z.any()),
+      file: z.instanceof(Readable).and(z.object({ truncated: z.boolean(), bytesRead: z.number() }).passthrough()),
+      fieldname: z.string(),
+      filename: z.string(),
+      encoding: z.string(),
+      mimetype: z.string(),
+      fields: z.record(z.any()),
+    })
+    .passthrough();
diff --git a/servers/noMulter/api/$relay.ts b/servers/noMulter/api/$relay.ts
index 1cfe169b..686fd3dc 100644
--- a/servers/noMulter/api/$relay.ts
+++ b/servers/noMulter/api/$relay.ts
@@ -24,13 +24,15 @@ export function defineController<M extends ServerMethods, T extends Record<strin
 }
 
 export const multipartFileValidator = (): z.ZodType<MultipartFile> =>
-  z.object({
-    type: z.literal('file'),
-    toBuffer: z.function().returns(z.promise(z.instanceof(Buffer))),
-    file: z.instanceof(Readable).and(z.object({ truncated: z.boolean(), bytesRead: z.number() })),
-    fieldname: z.string(),
-    filename: z.string(),
-    encoding: z.string(),
-    mimetype: z.string(),
-    fields: z.record(z.any()),
-  });
+  z
+    .object({
+      type: z.literal('file'),
+      toBuffer: z.function().returns(z.any()),
+      file: z.instanceof(Readable).and(z.object({ truncated: z.boolean(), bytesRead: z.number() }).passthrough()),
+      fieldname: z.string(),
+      filename: z.string(),
+      encoding: z.string(),
+      mimetype: z.string(),
+      fields: z.record(z.any()),
+    })
+    .passthrough();
diff --git a/servers/noMulter/api/empty/$relay.ts b/servers/noMulter/api/empty/$relay.ts
index fec711cc..e7301674 100644
--- a/servers/noMulter/api/empty/$relay.ts
+++ b/servers/noMulter/api/empty/$relay.ts
@@ -24,13 +24,15 @@ export function defineController<M extends ServerMethods, T extends Record<strin
 }
 
 export const multipartFileValidator = (): z.ZodType<MultipartFile> =>
-  z.object({
-    type: z.literal('file'),
-    toBuffer: z.function().returns(z.promise(z.instanceof(Buffer))),
-    file: z.instanceof(Readable).and(z.object({ truncated: z.boolean(), bytesRead: z.number() })),
-    fieldname: z.string(),
-    filename: z.string(),
-    encoding: z.string(),
-    mimetype: z.string(),
-    fields: z.record(z.any()),
-  });
+  z
+    .object({
+      type: z.literal('file'),
+      toBuffer: z.function().returns(z.any()),
+      file: z.instanceof(Readable).and(z.object({ truncated: z.boolean(), bytesRead: z.number() }).passthrough()),
+      fieldname: z.string(),
+      filename: z.string(),
+      encoding: z.string(),
+      mimetype: z.string(),
+      fields: z.record(z.any()),
+    })
+    .passthrough();
diff --git a/servers/noMulter/api/empty/noEmpty/$relay.ts b/servers/noMulter/api/empty/noEmpty/$relay.ts
index 1dd6e479..3bb599b1 100644
--- a/servers/noMulter/api/empty/noEmpty/$relay.ts
+++ b/servers/noMulter/api/empty/noEmpty/$relay.ts
@@ -24,13 +24,15 @@ export function defineController<M extends ServerMethods, T extends Record<strin
 }
 
 export const multipartFileValidator = (): z.ZodType<MultipartFile> =>
-  z.object({
-    type: z.literal('file'),
-    toBuffer: z.function().returns(z.promise(z.instanceof(Buffer))),
-    file: z.instanceof(Readable).and(z.object({ truncated: z.boolean(), bytesRead: z.number() })),
-    fieldname: z.string(),
-    filename: z.string(),
-    encoding: z.string(),
-    mimetype: z.string(),
-    fields: z.record(z.any()),
-  });
+  z
+    .object({
+      type: z.literal('file'),
+      toBuffer: z.function().returns(z.any()),
+      file: z.instanceof(Readable).and(z.object({ truncated: z.boolean(), bytesRead: z.number() }).passthrough()),
+      fieldname: z.string(),
+      filename: z.string(),
+      encoding: z.string(),
+      mimetype: z.string(),
+      fields: z.record(z.any()),
+    })
+    .passthrough();
diff --git a/servers/noMulter/api/texts/$relay.ts b/servers/noMulter/api/texts/$relay.ts
index fec711cc..e7301674 100644
--- a/servers/noMulter/api/texts/$relay.ts
+++ b/servers/noMulter/api/texts/$relay.ts
@@ -24,13 +24,15 @@ export function defineController<M extends ServerMethods, T extends Record<strin
 }
 
 export const multipartFileValidator = (): z.ZodType<MultipartFile> =>
-  z.object({
-    type: z.literal('file'),
-    toBuffer: z.function().returns(z.promise(z.instanceof(Buffer))),
-    file: z.instanceof(Readable).and(z.object({ truncated: z.boolean(), bytesRead: z.number() })),
-    fieldname: z.string(),
-    filename: z.string(),
-    encoding: z.string(),
-    mimetype: z.string(),
-    fields: z.record(z.any()),
-  });
+  z
+    .object({
+      type: z.literal('file'),
+      toBuffer: z.function().returns(z.any()),
+      file: z.instanceof(Readable).and(z.object({ truncated: z.boolean(), bytesRead: z.number() }).passthrough()),
+      fieldname: z.string(),
+      filename: z.string(),
+      encoding: z.string(),
+      mimetype: z.string(),
+      fields: z.record(z.any()),
+    })
+    .passthrough();
diff --git a/servers/noMulter/api/texts/sample/$relay.ts b/servers/noMulter/api/texts/sample/$relay.ts
index 1dd6e479..3bb599b1 100644
--- a/servers/noMulter/api/texts/sample/$relay.ts
+++ b/servers/noMulter/api/texts/sample/$relay.ts
@@ -24,13 +24,15 @@ export function defineController<M extends ServerMethods, T extends Record<strin
 }
 
 export const multipartFileValidator = (): z.ZodType<MultipartFile> =>
-  z.object({
-    type: z.literal('file'),
-    toBuffer: z.function().returns(z.promise(z.instanceof(Buffer))),
-    file: z.instanceof(Readable).and(z.object({ truncated: z.boolean(), bytesRead: z.number() })),
-    fieldname: z.string(),
-    filename: z.string(),
-    encoding: z.string(),
-    mimetype: z.string(),
-    fields: z.record(z.any()),
-  });
+  z
+    .object({
+      type: z.literal('file'),
+      toBuffer: z.function().returns(z.any()),
+      file: z.instanceof(Readable).and(z.object({ truncated: z.boolean(), bytesRead: z.number() }).passthrough()),
+      fieldname: z.string(),
+      filename: z.string(),
+      encoding: z.string(),
+      mimetype: z.string(),
+      fields: z.record(z.any()),
+    })
+    .passthrough();
diff --git a/servers/noMulter/api/users/$relay.ts b/servers/noMulter/api/users/$relay.ts
index 98c01ce0..2ff124f2 100644
--- a/servers/noMulter/api/users/$relay.ts
+++ b/servers/noMulter/api/users/$relay.ts
@@ -25,13 +25,15 @@ export function defineController<M extends ServerMethods, T extends Record<strin
 }
 
 export const multipartFileValidator = (): z.ZodType<MultipartFile> =>
-  z.object({
-    type: z.literal('file'),
-    toBuffer: z.function().returns(z.promise(z.instanceof(Buffer))),
-    file: z.instanceof(Readable).and(z.object({ truncated: z.boolean(), bytesRead: z.number() })),
-    fieldname: z.string(),
-    filename: z.string(),
-    encoding: z.string(),
-    mimetype: z.string(),
-    fields: z.record(z.any()),
-  });
+  z
+    .object({
+      type: z.literal('file'),
+      toBuffer: z.function().returns(z.any()),
+      file: z.instanceof(Readable).and(z.object({ truncated: z.boolean(), bytesRead: z.number() }).passthrough()),
+      fieldname: z.string(),
+      filename: z.string(),
+      encoding: z.string(),
+      mimetype: z.string(),
+      fields: z.record(z.any()),
+    })
+    .passthrough();
diff --git a/servers/noMulter/api/users/_userId@number/$relay.ts b/servers/noMulter/api/users/_userId@number/$relay.ts
index 420c8243..0dad67c5 100644
--- a/servers/noMulter/api/users/_userId@number/$relay.ts
+++ b/servers/noMulter/api/users/_userId@number/$relay.ts
@@ -35,13 +35,15 @@ export function defineController<M extends ServerMethods, T extends Record<strin
 }
 
 export const multipartFileValidator = (): z.ZodType<MultipartFile> =>
-  z.object({
-    type: z.literal('file'),
-    toBuffer: z.function().returns(z.promise(z.instanceof(Buffer))),
-    file: z.instanceof(Readable).and(z.object({ truncated: z.boolean(), bytesRead: z.number() })),
-    fieldname: z.string(),
-    filename: z.string(),
-    encoding: z.string(),
-    mimetype: z.string(),
-    fields: z.record(z.any()),
-  });
+  z
+    .object({
+      type: z.literal('file'),
+      toBuffer: z.function().returns(z.any()),
+      file: z.instanceof(Readable).and(z.object({ truncated: z.boolean(), bytesRead: z.number() }).passthrough()),
+      fieldname: z.string(),
+      filename: z.string(),
+      encoding: z.string(),
+      mimetype: z.string(),
+      fields: z.record(z.any()),
+    })
+    .passthrough();
diff --git a/servers/noTypedParams/api/$relay.ts b/servers/noTypedParams/api/$relay.ts
index 1cfe169b..686fd3dc 100644
--- a/servers/noTypedParams/api/$relay.ts
+++ b/servers/noTypedParams/api/$relay.ts
@@ -24,13 +24,15 @@ export function defineController<M extends ServerMethods, T extends Record<strin
 }
 
 export const multipartFileValidator = (): z.ZodType<MultipartFile> =>
-  z.object({
-    type: z.literal('file'),
-    toBuffer: z.function().returns(z.promise(z.instanceof(Buffer))),
-    file: z.instanceof(Readable).and(z.object({ truncated: z.boolean(), bytesRead: z.number() })),
-    fieldname: z.string(),
-    filename: z.string(),
-    encoding: z.string(),
-    mimetype: z.string(),
-    fields: z.record(z.any()),
-  });
+  z
+    .object({
+      type: z.literal('file'),
+      toBuffer: z.function().returns(z.any()),
+      file: z.instanceof(Readable).and(z.object({ truncated: z.boolean(), bytesRead: z.number() }).passthrough()),
+      fieldname: z.string(),
+      filename: z.string(),
+      encoding: z.string(),
+      mimetype: z.string(),
+      fields: z.record(z.any()),
+    })
+    .passthrough();
diff --git a/servers/noTypedParams/api/empty/$relay.ts b/servers/noTypedParams/api/empty/$relay.ts
index fec711cc..e7301674 100644
--- a/servers/noTypedParams/api/empty/$relay.ts
+++ b/servers/noTypedParams/api/empty/$relay.ts
@@ -24,13 +24,15 @@ export function defineController<M extends ServerMethods, T extends Record<strin
 }
 
 export const multipartFileValidator = (): z.ZodType<MultipartFile> =>
-  z.object({
-    type: z.literal('file'),
-    toBuffer: z.function().returns(z.promise(z.instanceof(Buffer))),
-    file: z.instanceof(Readable).and(z.object({ truncated: z.boolean(), bytesRead: z.number() })),
-    fieldname: z.string(),
-    filename: z.string(),
-    encoding: z.string(),
-    mimetype: z.string(),
-    fields: z.record(z.any()),
-  });
+  z
+    .object({
+      type: z.literal('file'),
+      toBuffer: z.function().returns(z.any()),
+      file: z.instanceof(Readable).and(z.object({ truncated: z.boolean(), bytesRead: z.number() }).passthrough()),
+      fieldname: z.string(),
+      filename: z.string(),
+      encoding: z.string(),
+      mimetype: z.string(),
+      fields: z.record(z.any()),
+    })
+    .passthrough();
diff --git a/servers/noTypedParams/api/empty/noEmpty/$relay.ts b/servers/noTypedParams/api/empty/noEmpty/$relay.ts
index 1dd6e479..3bb599b1 100644
--- a/servers/noTypedParams/api/empty/noEmpty/$relay.ts
+++ b/servers/noTypedParams/api/empty/noEmpty/$relay.ts
@@ -24,13 +24,15 @@ export function defineController<M extends ServerMethods, T extends Record<strin
 }
 
 export const multipartFileValidator = (): z.ZodType<MultipartFile> =>
-  z.object({
-    type: z.literal('file'),
-    toBuffer: z.function().returns(z.promise(z.instanceof(Buffer))),
-    file: z.instanceof(Readable).and(z.object({ truncated: z.boolean(), bytesRead: z.number() })),
-    fieldname: z.string(),
-    filename: z.string(),
-    encoding: z.string(),
-    mimetype: z.string(),
-    fields: z.record(z.any()),
-  });
+  z
+    .object({
+      type: z.literal('file'),
+      toBuffer: z.function().returns(z.any()),
+      file: z.instanceof(Readable).and(z.object({ truncated: z.boolean(), bytesRead: z.number() }).passthrough()),
+      fieldname: z.string(),
+      filename: z.string(),
+      encoding: z.string(),
+      mimetype: z.string(),
+      fields: z.record(z.any()),
+    })
+    .passthrough();
diff --git a/servers/noTypedParams/api/multiForm/$relay.ts b/servers/noTypedParams/api/multiForm/$relay.ts
index fec711cc..e7301674 100644
--- a/servers/noTypedParams/api/multiForm/$relay.ts
+++ b/servers/noTypedParams/api/multiForm/$relay.ts
@@ -24,13 +24,15 @@ export function defineController<M extends ServerMethods, T extends Record<strin
 }
 
 export const multipartFileValidator = (): z.ZodType<MultipartFile> =>
-  z.object({
-    type: z.literal('file'),
-    toBuffer: z.function().returns(z.promise(z.instanceof(Buffer))),
-    file: z.instanceof(Readable).and(z.object({ truncated: z.boolean(), bytesRead: z.number() })),
-    fieldname: z.string(),
-    filename: z.string(),
-    encoding: z.string(),
-    mimetype: z.string(),
-    fields: z.record(z.any()),
-  });
+  z
+    .object({
+      type: z.literal('file'),
+      toBuffer: z.function().returns(z.any()),
+      file: z.instanceof(Readable).and(z.object({ truncated: z.boolean(), bytesRead: z.number() }).passthrough()),
+      fieldname: z.string(),
+      filename: z.string(),
+      encoding: z.string(),
+      mimetype: z.string(),
+      fields: z.record(z.any()),
+    })
+    .passthrough();
diff --git a/servers/noTypedParams/api/texts/$relay.ts b/servers/noTypedParams/api/texts/$relay.ts
index fec711cc..e7301674 100644
--- a/servers/noTypedParams/api/texts/$relay.ts
+++ b/servers/noTypedParams/api/texts/$relay.ts
@@ -24,13 +24,15 @@ export function defineController<M extends ServerMethods, T extends Record<strin
 }
 
 export const multipartFileValidator = (): z.ZodType<MultipartFile> =>
-  z.object({
-    type: z.literal('file'),
-    toBuffer: z.function().returns(z.promise(z.instanceof(Buffer))),
-    file: z.instanceof(Readable).and(z.object({ truncated: z.boolean(), bytesRead: z.number() })),
-    fieldname: z.string(),
-    filename: z.string(),
-    encoding: z.string(),
-    mimetype: z.string(),
-    fields: z.record(z.any()),
-  });
+  z
+    .object({
+      type: z.literal('file'),
+      toBuffer: z.function().returns(z.any()),
+      file: z.instanceof(Readable).and(z.object({ truncated: z.boolean(), bytesRead: z.number() }).passthrough()),
+      fieldname: z.string(),
+      filename: z.string(),
+      encoding: z.string(),
+      mimetype: z.string(),
+      fields: z.record(z.any()),
+    })
+    .passthrough();
diff --git a/servers/noTypedParams/api/texts/sample/$relay.ts b/servers/noTypedParams/api/texts/sample/$relay.ts
index 1dd6e479..3bb599b1 100644
--- a/servers/noTypedParams/api/texts/sample/$relay.ts
+++ b/servers/noTypedParams/api/texts/sample/$relay.ts
@@ -24,13 +24,15 @@ export function defineController<M extends ServerMethods, T extends Record<strin
 }
 
 export const multipartFileValidator = (): z.ZodType<MultipartFile> =>
-  z.object({
-    type: z.literal('file'),
-    toBuffer: z.function().returns(z.promise(z.instanceof(Buffer))),
-    file: z.instanceof(Readable).and(z.object({ truncated: z.boolean(), bytesRead: z.number() })),
-    fieldname: z.string(),
-    filename: z.string(),
-    encoding: z.string(),
-    mimetype: z.string(),
-    fields: z.record(z.any()),
-  });
+  z
+    .object({
+      type: z.literal('file'),
+      toBuffer: z.function().returns(z.any()),
+      file: z.instanceof(Readable).and(z.object({ truncated: z.boolean(), bytesRead: z.number() }).passthrough()),
+      fieldname: z.string(),
+      filename: z.string(),
+      encoding: z.string(),
+      mimetype: z.string(),
+      fields: z.record(z.any()),
+    })
+    .passthrough();
diff --git a/servers/noTypedParams/api/users/$relay.ts b/servers/noTypedParams/api/users/$relay.ts
index 98c01ce0..2ff124f2 100644
--- a/servers/noTypedParams/api/users/$relay.ts
+++ b/servers/noTypedParams/api/users/$relay.ts
@@ -25,13 +25,15 @@ export function defineController<M extends ServerMethods, T extends Record<strin
 }
 
 export const multipartFileValidator = (): z.ZodType<MultipartFile> =>
-  z.object({
-    type: z.literal('file'),
-    toBuffer: z.function().returns(z.promise(z.instanceof(Buffer))),
-    file: z.instanceof(Readable).and(z.object({ truncated: z.boolean(), bytesRead: z.number() })),
-    fieldname: z.string(),
-    filename: z.string(),
-    encoding: z.string(),
-    mimetype: z.string(),
-    fields: z.record(z.any()),
-  });
+  z
+    .object({
+      type: z.literal('file'),
+      toBuffer: z.function().returns(z.any()),
+      file: z.instanceof(Readable).and(z.object({ truncated: z.boolean(), bytesRead: z.number() }).passthrough()),
+      fieldname: z.string(),
+      filename: z.string(),
+      encoding: z.string(),
+      mimetype: z.string(),
+      fields: z.record(z.any()),
+    })
+    .passthrough();
diff --git a/servers/noValidator/api/$relay.ts b/servers/noValidator/api/$relay.ts
index 1cfe169b..686fd3dc 100644
--- a/servers/noValidator/api/$relay.ts
+++ b/servers/noValidator/api/$relay.ts
@@ -24,13 +24,15 @@ export function defineController<M extends ServerMethods, T extends Record<strin
 }
 
 export const multipartFileValidator = (): z.ZodType<MultipartFile> =>
-  z.object({
-    type: z.literal('file'),
-    toBuffer: z.function().returns(z.promise(z.instanceof(Buffer))),
-    file: z.instanceof(Readable).and(z.object({ truncated: z.boolean(), bytesRead: z.number() })),
-    fieldname: z.string(),
-    filename: z.string(),
-    encoding: z.string(),
-    mimetype: z.string(),
-    fields: z.record(z.any()),
-  });
+  z
+    .object({
+      type: z.literal('file'),
+      toBuffer: z.function().returns(z.any()),
+      file: z.instanceof(Readable).and(z.object({ truncated: z.boolean(), bytesRead: z.number() }).passthrough()),
+      fieldname: z.string(),
+      filename: z.string(),
+      encoding: z.string(),
+      mimetype: z.string(),
+      fields: z.record(z.any()),
+    })
+    .passthrough();
diff --git a/servers/noValidator/api/empty/$relay.ts b/servers/noValidator/api/empty/$relay.ts
index fec711cc..e7301674 100644
--- a/servers/noValidator/api/empty/$relay.ts
+++ b/servers/noValidator/api/empty/$relay.ts
@@ -24,13 +24,15 @@ export function defineController<M extends ServerMethods, T extends Record<strin
 }
 
 export const multipartFileValidator = (): z.ZodType<MultipartFile> =>
-  z.object({
-    type: z.literal('file'),
-    toBuffer: z.function().returns(z.promise(z.instanceof(Buffer))),
-    file: z.instanceof(Readable).and(z.object({ truncated: z.boolean(), bytesRead: z.number() })),
-    fieldname: z.string(),
-    filename: z.string(),
-    encoding: z.string(),
-    mimetype: z.string(),
-    fields: z.record(z.any()),
-  });
+  z
+    .object({
+      type: z.literal('file'),
+      toBuffer: z.function().returns(z.any()),
+      file: z.instanceof(Readable).and(z.object({ truncated: z.boolean(), bytesRead: z.number() }).passthrough()),
+      fieldname: z.string(),
+      filename: z.string(),
+      encoding: z.string(),
+      mimetype: z.string(),
+      fields: z.record(z.any()),
+    })
+    .passthrough();
diff --git a/servers/noValidator/api/empty/noEmpty/$relay.ts b/servers/noValidator/api/empty/noEmpty/$relay.ts
index 1dd6e479..3bb599b1 100644
--- a/servers/noValidator/api/empty/noEmpty/$relay.ts
+++ b/servers/noValidator/api/empty/noEmpty/$relay.ts
@@ -24,13 +24,15 @@ export function defineController<M extends ServerMethods, T extends Record<strin
 }
 
 export const multipartFileValidator = (): z.ZodType<MultipartFile> =>
-  z.object({
-    type: z.literal('file'),
-    toBuffer: z.function().returns(z.promise(z.instanceof(Buffer))),
-    file: z.instanceof(Readable).and(z.object({ truncated: z.boolean(), bytesRead: z.number() })),
-    fieldname: z.string(),
-    filename: z.string(),
-    encoding: z.string(),
-    mimetype: z.string(),
-    fields: z.record(z.any()),
-  });
+  z
+    .object({
+      type: z.literal('file'),
+      toBuffer: z.function().returns(z.any()),
+      file: z.instanceof(Readable).and(z.object({ truncated: z.boolean(), bytesRead: z.number() }).passthrough()),
+      fieldname: z.string(),
+      filename: z.string(),
+      encoding: z.string(),
+      mimetype: z.string(),
+      fields: z.record(z.any()),
+    })
+    .passthrough();
diff --git a/servers/noValidator/api/multiForm/$relay.ts b/servers/noValidator/api/multiForm/$relay.ts
index fec711cc..e7301674 100644
--- a/servers/noValidator/api/multiForm/$relay.ts
+++ b/servers/noValidator/api/multiForm/$relay.ts
@@ -24,13 +24,15 @@ export function defineController<M extends ServerMethods, T extends Record<strin
 }
 
 export const multipartFileValidator = (): z.ZodType<MultipartFile> =>
-  z.object({
-    type: z.literal('file'),
-    toBuffer: z.function().returns(z.promise(z.instanceof(Buffer))),
-    file: z.instanceof(Readable).and(z.object({ truncated: z.boolean(), bytesRead: z.number() })),
-    fieldname: z.string(),
-    filename: z.string(),
-    encoding: z.string(),
-    mimetype: z.string(),
-    fields: z.record(z.any()),
-  });
+  z
+    .object({
+      type: z.literal('file'),
+      toBuffer: z.function().returns(z.any()),
+      file: z.instanceof(Readable).and(z.object({ truncated: z.boolean(), bytesRead: z.number() }).passthrough()),
+      fieldname: z.string(),
+      filename: z.string(),
+      encoding: z.string(),
+      mimetype: z.string(),
+      fields: z.record(z.any()),
+    })
+    .passthrough();
diff --git a/servers/noValidator/api/texts/$relay.ts b/servers/noValidator/api/texts/$relay.ts
index fec711cc..e7301674 100644
--- a/servers/noValidator/api/texts/$relay.ts
+++ b/servers/noValidator/api/texts/$relay.ts
@@ -24,13 +24,15 @@ export function defineController<M extends ServerMethods, T extends Record<strin
 }
 
 export const multipartFileValidator = (): z.ZodType<MultipartFile> =>
-  z.object({
-    type: z.literal('file'),
-    toBuffer: z.function().returns(z.promise(z.instanceof(Buffer))),
-    file: z.instanceof(Readable).and(z.object({ truncated: z.boolean(), bytesRead: z.number() })),
-    fieldname: z.string(),
-    filename: z.string(),
-    encoding: z.string(),
-    mimetype: z.string(),
-    fields: z.record(z.any()),
-  });
+  z
+    .object({
+      type: z.literal('file'),
+      toBuffer: z.function().returns(z.any()),
+      file: z.instanceof(Readable).and(z.object({ truncated: z.boolean(), bytesRead: z.number() }).passthrough()),
+      fieldname: z.string(),
+      filename: z.string(),
+      encoding: z.string(),
+      mimetype: z.string(),
+      fields: z.record(z.any()),
+    })
+    .passthrough();
diff --git a/servers/noValidator/api/texts/sample/$relay.ts b/servers/noValidator/api/texts/sample/$relay.ts
index 1dd6e479..3bb599b1 100644
--- a/servers/noValidator/api/texts/sample/$relay.ts
+++ b/servers/noValidator/api/texts/sample/$relay.ts
@@ -24,13 +24,15 @@ export function defineController<M extends ServerMethods, T extends Record<strin
 }
 
 export const multipartFileValidator = (): z.ZodType<MultipartFile> =>
-  z.object({
-    type: z.literal('file'),
-    toBuffer: z.function().returns(z.promise(z.instanceof(Buffer))),
-    file: z.instanceof(Readable).and(z.object({ truncated: z.boolean(), bytesRead: z.number() })),
-    fieldname: z.string(),
-    filename: z.string(),
-    encoding: z.string(),
-    mimetype: z.string(),
-    fields: z.record(z.any()),
-  });
+  z
+    .object({
+      type: z.literal('file'),
+      toBuffer: z.function().returns(z.any()),
+      file: z.instanceof(Readable).and(z.object({ truncated: z.boolean(), bytesRead: z.number() }).passthrough()),
+      fieldname: z.string(),
+      filename: z.string(),
+      encoding: z.string(),
+      mimetype: z.string(),
+      fields: z.record(z.any()),
+    })
+    .passthrough();
diff --git a/servers/noValidator/api/users/$relay.ts b/servers/noValidator/api/users/$relay.ts
index 98c01ce0..2ff124f2 100644
--- a/servers/noValidator/api/users/$relay.ts
+++ b/servers/noValidator/api/users/$relay.ts
@@ -25,13 +25,15 @@ export function defineController<M extends ServerMethods, T extends Record<strin
 }
 
 export const multipartFileValidator = (): z.ZodType<MultipartFile> =>
-  z.object({
-    type: z.literal('file'),
-    toBuffer: z.function().returns(z.promise(z.instanceof(Buffer))),
-    file: z.instanceof(Readable).and(z.object({ truncated: z.boolean(), bytesRead: z.number() })),
-    fieldname: z.string(),
-    filename: z.string(),
-    encoding: z.string(),
-    mimetype: z.string(),
-    fields: z.record(z.any()),
-  });
+  z
+    .object({
+      type: z.literal('file'),
+      toBuffer: z.function().returns(z.any()),
+      file: z.instanceof(Readable).and(z.object({ truncated: z.boolean(), bytesRead: z.number() }).passthrough()),
+      fieldname: z.string(),
+      filename: z.string(),
+      encoding: z.string(),
+      mimetype: z.string(),
+      fields: z.record(z.any()),
+    })
+    .passthrough();
diff --git a/servers/noValidator/api/users/_userId@number/$relay.ts b/servers/noValidator/api/users/_userId@number/$relay.ts
index 420c8243..0dad67c5 100644
--- a/servers/noValidator/api/users/_userId@number/$relay.ts
+++ b/servers/noValidator/api/users/_userId@number/$relay.ts
@@ -35,13 +35,15 @@ export function defineController<M extends ServerMethods, T extends Record<strin
 }
 
 export const multipartFileValidator = (): z.ZodType<MultipartFile> =>
-  z.object({
-    type: z.literal('file'),
-    toBuffer: z.function().returns(z.promise(z.instanceof(Buffer))),
-    file: z.instanceof(Readable).and(z.object({ truncated: z.boolean(), bytesRead: z.number() })),
-    fieldname: z.string(),
-    filename: z.string(),
-    encoding: z.string(),
-    mimetype: z.string(),
-    fields: z.record(z.any()),
-  });
+  z
+    .object({
+      type: z.literal('file'),
+      toBuffer: z.function().returns(z.any()),
+      file: z.instanceof(Readable).and(z.object({ truncated: z.boolean(), bytesRead: z.number() }).passthrough()),
+      fieldname: z.string(),
+      filename: z.string(),
+      encoding: z.string(),
+      mimetype: z.string(),
+      fields: z.record(z.any()),
+    })
+    .passthrough();
diff --git a/src/createControllersText.ts b/src/createControllersText.ts
index 55b2262c..5110dcdf 100644
--- a/src/createControllersText.ts
+++ b/src/createControllersText.ts
@@ -122,16 +122,18 @@ export function defineController<M extends ServerMethods, T extends Record<strin
 }
 
 export const multipartFileValidator = (): z.ZodType<MultipartFile> =>
-  z.object({
-    type: z.literal('file'),
-    toBuffer: z.function().returns(z.promise(z.instanceof(Buffer))),
-    file: z.instanceof(Readable).and(z.object({ truncated: z.boolean(), bytesRead: z.number() })),
-    fieldname: z.string(),
-    filename: z.string(),
-    encoding: z.string(),
-    mimetype: z.string(),
-    fields: z.record(z.any()),
-  });
+  z
+    .object({
+      type: z.literal('file'),
+      toBuffer: z.function().returns(z.any()),
+      file: z.instanceof(Readable).and(z.object({ truncated: z.boolean(), bytesRead: z.number() }).passthrough()),
+      fieldname: z.string(),
+      filename: z.string(),
+      encoding: z.string(),
+      mimetype: z.string(),
+      fields: z.record(z.any()),
+    })
+    .passthrough();
 `;
 
   fs.writeFileSync(