diff --git a/src/ZodSchemaClass.ts b/src/ZodSchemaClass.ts
index 697cf68..d968ecf 100644
--- a/src/ZodSchemaClass.ts
+++ b/src/ZodSchemaClass.ts
@@ -1,6 +1,7 @@
 import { expression } from "@thilawyn/traitify-ts"
 import { AbstractClass } from "type-fest"
 import { z } from "zod"
+import { ExtendableZodSchemaObject } from "./traits/ExtendableZodSchemaObject"
 import { InstantiableZodSchemaObject } from "./traits/InstantiableZodSchemaObject"
 import { Extend, StaticMembers } from "./util"
 
@@ -32,7 +33,10 @@ export function ZodSchemaClassOf<
                 Object.assign(this, values)
             }
         })
-        .expresses(InstantiableZodSchemaObject)
+        .expresses(
+            InstantiableZodSchemaObject,
+            ExtendableZodSchemaObject,
+        )
         .build()
 
     return exp.extends as AbstractClass<
diff --git a/src/tests.ts b/src/tests.ts
index 682c96a..ded48e8 100644
--- a/src/tests.ts
+++ b/src/tests.ts
@@ -26,17 +26,17 @@ const inst = Test.create({ id: 1n, name: "" })
 console.log(inst)
 
 
-// class SubTest extends Test.extend({
-//     schema: ({ schema }) => schema.extend({
-//         prout: z.string()
-//     }),
+class SubTest extends Test.extend({
+    schema: ({ schema }) => schema.extend({
+        prout: z.string()
+    }),
 
-//     defaultValues: defaultValues => defineDefaultValues({
-//         ...defaultValues
-//     }),
-// }) {}
+    defaultValues: defaultValues => ({
+        ...defaultValues
+    }),
+}) {}
 
-// const subInst = await SubTest.createPromise({ name: "", prout: "" })
+const subInst = await SubTest.createPromise({ name: "", prout: "" })
 
 // console.log(subInst)
 
diff --git a/src/traits/ExtendableZodSchemaObject.ts b/src/traits/ExtendableZodSchemaObject.ts
index ab1be36..dacb7bb 100644
--- a/src/traits/ExtendableZodSchemaObject.ts
+++ b/src/traits/ExtendableZodSchemaObject.ts
@@ -1,6 +1,8 @@
 import { abstract, trait } from "@thilawyn/traitify-ts"
+import { AbstractClass } from "type-fest"
 import { z } from "zod"
 import { ZodSchemaAbstractClass } from "../types/ZodSchemaClass"
+import { Extend, StaticMembers } from "../util"
 
 
 export const ExtendableZodSchemaObject = trait(
@@ -32,8 +34,26 @@ export const ExtendableZodSchemaObject = trait(
 
                 defaultValues: (defaultValues: SuperDefaultValues) => DefaultValues
             },
+        ): (
+            AbstractClass<
+                Extend<[InstanceType<Super>, Values]>,
+                [values: Values]
+            > &
+            Extend<[
+                StaticMembers<Super>,
+                {
+                    readonly schema:         z.ZodObject<SchemaT, SchemaUnknownKeys, SchemaCatchall, Values, Values>,
+                    readonly defaultValues:  DefaultValues,
+                },
+            ]>
         ) {
+            const schema        = props.schema({ schema: this.schema, shape: this.schema.shape })
+            const defaultValues = props.defaultValues(this.defaultValues)
 
+            return class extends this {
+                static readonly schema        = schema
+                static readonly defaultValues = defaultValues
+            } as any
         }
     },
 )
diff --git a/src/traits/InstantiableZodSchemaObject.ts b/src/traits/InstantiableZodSchemaObject.ts
index 2560cfc..fb70ca9 100644
--- a/src/traits/InstantiableZodSchemaObject.ts
+++ b/src/traits/InstantiableZodSchemaObject.ts
@@ -1,11 +1,31 @@
 import { abstract, trait } from "@thilawyn/traitify-ts"
 import { Effect, pipe } from "effect"
+import { HasRequiredKeys } from "type-fest"
 import { z } from "zod"
-import { NewZodSchemaInstanceArgs, NewZodSchemaInstanceInput } from ".."
 import { ZodSchemaClass } from "../types/ZodSchemaClass"
 import { parseZodTypeEffect } from "../util"
 
 
+type NewZodSchemaInstanceInput<
+    Values        extends {},
+    DefaultValues extends Partial<Values>,
+> = {
+    [Key in Exclude<keyof Values, keyof DefaultValues>]: Values[Key]
+} & {
+    [Key in keyof DefaultValues]?: Key extends keyof Values
+        ? Values[Key]
+        : never
+}
+
+type ParseParamsArgs = [] | [params: Partial<z.ParseParams>]
+
+type NewZodSchemaInstanceArgs<Input extends object> = (
+    HasRequiredKeys<Input> extends true
+        ? [values: Input, ...args: ParseParamsArgs]
+        : [] | [values: Input, ...args: ParseParamsArgs]
+)
+
+
 export const InstantiableZodSchemaObject = trait(
     abstract(),