diff --git a/src/effect/EffectSchemaTraitExpression.ts b/src/effect/EffectSchemaTraitExpression.ts
index a791036..f42b0d9 100644
--- a/src/effect/EffectSchemaTraitExpression.ts
+++ b/src/effect/EffectSchemaTraitExpression.ts
@@ -1,8 +1,14 @@
 import { Schema as S } from "@effect/schema"
-import { Simplify } from "type-fest"
+import { AbstractClass, AbstractConstructor, Simplify } from "type-fest"
 import { Trait, TraitTuple } from "../Trait"
 import { StaticImplements, TraitExpressionLike } from "../TraitExpression"
-import { Extend } from "../util"
+import { Extend, StaticMembers } from "../util"
+import { Types } from "effect"
+
+
+type RequiredKeys<T> = {
+    [K in keyof T]-?: {} extends Pick<T, K> ? never : K
+  }[keyof T]
 
 
 export class EffectSchemaTraitExpression<
@@ -26,17 +32,30 @@ implements TraitExpressionLike<
 
 
     extends<Self>(): (
-        S.Class<
-            Self,
-            Fields,
-            I, R, C,
-            Simplify<
-                Extend<[
-                    Inherited,
-                    ...TraitTuple.MapImplInstance<Traits>
-                ]>
-            >,
-            Proto
+        AbstractConstructor<
+            S.Struct.Type<Fields> &
+            Omit<Inherited, keyof Fields> &
+            Proto,
+
+            [
+                props: RequiredKeys<C> extends never ? void | {} : Types.Simplify<C>,
+                disableValidation?: boolean | undefined
+            ]
+        > &
+
+        StaticMembers<
+            S.Class<
+                Self,
+                Fields,
+                I, R, C,
+                Simplify<
+                    Extend<[
+                        Inherited,
+                        ...TraitTuple.MapImplInstance<Traits>
+                    ]>
+                >,
+                Proto
+            >
         > &
 
         Simplify<