diff --git a/pkgs/pow-captcha/package.json b/pkgs/pow-captcha/package.json
index 22b1163..4b7c9a5 100644
--- a/pkgs/pow-captcha/package.json
+++ b/pkgs/pow-captcha/package.json
@@ -10,6 +10,6 @@
 	},
 	"dependencies": {
 		"base64-js": "^1.5.1",
-		"zod": "^3.25.67"
+		"zod": "^4"
 	}
 }
diff --git a/pkgs/pow-captcha/src/wire.ts b/pkgs/pow-captcha/src/wire.ts
index 265d8b5..54fc879 100644
--- a/pkgs/pow-captcha/src/wire.ts
+++ b/pkgs/pow-captcha/src/wire.ts
@@ -1,4 +1,4 @@
-import { z } from "zod";
+import * as z from "zod/mini";
 import {
 	fromByteArray as serializeArray,
 	toByteArray as deserializeArray,
@@ -52,7 +52,7 @@ export async function serializeAndSignData<T>(
 
 export async function verifyAndDeserializeData<T>(
 	signedData: SignedData,
-	schema: z.ZodType<T>,
+	schema: z.ZodMiniType<T>,
 	secret: string,
 ): Promise<T> {
 	const arr = utf16StringToArrayBuffer(`${signedData.data}:${secret}`);
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index c3e717d..dac9e34 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -48,8 +48,8 @@ importers:
         specifier: ^1.5.1
         version: 1.5.1
       zod:
-        specifier: ^3.25.67
-        version: 3.25.67
+        specifier: ^4
+        version: 4.0.5
 
   pkgs/solver-wasm: {}
 
@@ -1811,8 +1811,8 @@ packages:
     resolution: {integrity: sha512-rVksvsnNCdJ/ohGc6xgPwyN8eheCxsiLM8mxuE/t/mOVqJewPuO1miLpTHQiRgTKCLexL4MeAFVagts7HmNZ2Q==}
     engines: {node: '>=10'}
 
-  zod@3.25.67:
-    resolution: {integrity: sha512-idA2YXwpCdqUSKRCACDE6ItZD9TZzy3OZMtpfLoh6oPR47lipysRrJfjzMqFxQ3uJuUPyUeWe1r9vLH33xO/Qw==}
+  zod@4.0.5:
+    resolution: {integrity: sha512-/5UuuRPStvHXu7RS+gmvRf4NXrNxpSllGwDnCBcJZtQsKrviYXm54yDGV2KYNLT5kq0lHGcl7lqWJLgSaG+tgA==}
 
 snapshots:
 
@@ -3837,4 +3837,4 @@ snapshots:
 
   yocto-queue@0.1.0: {}
 
-  zod@3.25.67: {}
+  zod@4.0.5: {}