diff --git a/zod/src/__tests__/zod-v3.ts b/zod/src/__tests__/zod-v3.ts
index 8e040ba..a979f10 100644
--- a/zod/src/__tests__/zod-v3.ts
+++ b/zod/src/__tests__/zod-v3.ts
@@ -175,4 +175,14 @@ describe('zodResolver', () => {
       }>
     >();
   });
+
+  it('should accept z.ZodType', () => {
+    // https://github.com/react-hook-form/resolvers/issues/782
+    const schema: z.ZodType<{ id: number }> = z.object({ id: z.number() });
+    const resolver = zodResolver(schema);
+
+    expectTypeOf(resolver).toEqualTypeOf<
+      Resolver<{ id: number }, unknown, { id: number }>
+    >();
+  });
 });
diff --git a/zod/src/zod.ts b/zod/src/zod.ts
index ff55dfc..0217e84 100644
--- a/zod/src/zod.ts
+++ b/zod/src/zod.ts
@@ -15,11 +15,7 @@ const isZod3Error = (error: any): error is z3.ZodError => {
   return Array.isArray(error?.issues);
 };
 const isZod3Schema = (schema: any): schema is z3.ZodSchema => {
-  return (
-    '_def' in schema &&
-    typeof schema._def === 'object' &&
-    'typeName' in schema._def
-  );
+  return '_def' in schema && typeof schema._def === 'object';
 };
 const isZod4Error = (error: any): error is z4.$ZodError => {
   // instanceof is safe in Zod 4 (uses Symbol.hasInstance)
@@ -143,9 +139,7 @@ type NonRawResolverOptions = {
 interface Zod3Type<O = unknown, I = unknown> {
   _output: O;
   _input: I;
-  _def: {
-    typeName: string;
-  };
+  _def: object;
 }
 
 // some type magic to make versions pre-3.25.0 still work