diff --git a/prisma/typebox/Post.ts b/prisma/typebox/Post.ts
index b7c923d..5ba899b 100644
--- a/prisma/typebox/Post.ts
+++ b/prisma/typebox/Post.ts
@@ -2,7 +2,7 @@ import { Type, Static } from "@sinclair/typebox";
 
 export const Post = Type.Object({
   id: Type.Number(),
-  userId: Type.Optional(Type.Number()),
+  userId: Type.Union([Type.Number(), Type.Null()]),
 });
 
 export type PostType = Static<typeof Post>;
diff --git a/prisma/typebox/User.ts b/prisma/typebox/User.ts
index 73327de..cd3a623 100644
--- a/prisma/typebox/User.ts
+++ b/prisma/typebox/User.ts
@@ -4,17 +4,17 @@ import { Role } from "./Role";
 export const User = Type.Object(
   {
     id: Type.Number(),
-    createdAt: Type.Optional(Type.String()),
+    createdAt: Type.Union([Type.String(), Type.Null()]),
     email: Type.String(),
-    weight: Type.Optional(Type.Number()),
-    is18: Type.Optional(Type.Boolean()),
-    name: Type.Optional(Type.String()),
-    successorId: Type.Optional(Type.Number()),
-    role: Type.Optional(Role),
+    weight: Type.Union([Type.Number(), Type.Null()]),
+    is18: Type.Union([Type.Boolean(), Type.Null()]),
+    name: Type.Union([Type.String(), Type.Null()]),
+    successorId: Type.Union([Type.Number(), Type.Null()]),
+    role: Type.Union([Role, Type.Null()]),
     posts: Type.Array(
       Type.Object({
         id: Type.Number(),
-        userId: Type.Optional(Type.Number()),
+        userId: Type.Union([Type.Number(), Type.Null()]),
       })
     ),
     keywords: Type.Array(Type.String({ minLength: 3 }), { maxItems: 10 }),
diff --git a/src/generator/transformDMMF.ts b/src/generator/transformDMMF.ts
index ba88423..80c5ab5 100644
--- a/src/generator/transformDMMF.ts
+++ b/src/generator/transformDMMF.ts
@@ -88,8 +88,8 @@ export function createTransformer(generatorName: string) {
     }
 
     if ((!field.isRequired || field.hasDefaultValue) && !field.isId) {
-      tokens.splice(1, 0, 'Type.Optional(');
-      tokens.splice(tokens.length, 0, ')');
+      tokens.splice(1, 0, 'Type.Union([');
+      tokens.splice(tokens.length, 0, ',Type.Null()])');
       inputTokens.splice(1, 0, 'Type.Optional(');
       inputTokens.splice(inputTokens.length, 0, ')');
     }