diff --git a/src/effect/schema/Jsonifiable.ts b/src/effect/schema/Jsonifiable.ts
index d1efbbb..14603f6 100644
--- a/src/effect/schema/Jsonifiable.ts
+++ b/src/effect/schema/Jsonifiable.ts
@@ -12,15 +12,28 @@ import type * as TF from "type-fest"
 //     return jsonifiable.pipe(S.compose(schema))
 // }
 
-export function Jsonifiable<
-    JsonifiableA extends I,
+export function Jsonifiable<A, I, R>(
+    schema: S.Schema<A, I, R>
+) {
+    return <
+        JsonifiableA extends I,
+        JsonifiableI extends TF.Jsonifiable,
+        JsonifiableR,
+    >(
+        jsonifiable: S.Schema<JsonifiableA, JsonifiableI, JsonifiableR>
+    ) =>
+        jsonifiable.pipe(S.compose(schema))
+}
+
+export function Jsonifiable2<
+    JsonifiableA,
     JsonifiableI extends TF.Jsonifiable,
     JsonifiableR,
 >(
     jsonifiable: S.Schema<JsonifiableA, JsonifiableI, JsonifiableR>
 ) {
-    return <A, I, R>(
-        schema: S.Schema<A, I, R>
+    return <A, R>(
+        schema: S.Schema<A, JsonifiableA, R>
     ) =>
         jsonifiable.pipe(S.compose(schema))
 }
diff --git a/src/effect/schema/class/MobXObservable.ts b/src/effect/schema/class/MobXObservable.ts
index cc47903..f967df0 100644
--- a/src/effect/schema/class/MobXObservable.ts
+++ b/src/effect/schema/class/MobXObservable.ts
@@ -3,18 +3,16 @@ import { makeObservable, observable, type CreateObservableOptions } from "mobx"
 import { mapValues } from "remeda"
 
 
-interface MobXObservableInput {
+interface MobXObservableA {
     new(...args: any[]): S.Struct.Type<S.Struct.Fields>
     readonly fields: { readonly [K in keyof S.Struct.Fields]: S.Struct.Fields[K] }
 }
 
-export function MobXObservable<
-    This extends MobXObservableInput
->(
-    class_:    This,
+export function MobXObservable<A extends MobXObservableA>(
+    self:      A,
     options?:  Omit<CreateObservableOptions, "proxy">,
 ) {
-    return class MobXObservable extends class_ {
+    return class MobXObservable extends self {
         declare ["constructor"]: typeof MobXObservable
 
         constructor(...args: any[]) {
@@ -25,5 +23,5 @@ export function MobXObservable<
                 options,
             )
         }
-    } as This
+    } as A
 }
diff --git a/src/effect/schema/tests.ts b/src/effect/schema/tests.ts
index 139187d..93e28f4 100644
--- a/src/effect/schema/tests.ts
+++ b/src/effect/schema/tests.ts
@@ -1,6 +1,6 @@
 import { Schema as S } from "@effect/schema"
 import { reaction, runInAction } from "mobx"
-import { Jsonifiable } from "./Jsonifiable"
+import { Jsonifiable2 } from "./Jsonifiable"
 import { MobXObservable, MutableTaggedClass } from "./class"
 
 
@@ -12,17 +12,12 @@ class User extends MutableTaggedClass<User>()("User", {
 ) {}
 
 const JsonifiableUser = User.pipe(
-    Jsonifiable(S.Struct({
+    Jsonifiable2(S.Struct({
         ...User.fields,
         id: S.BigInt,
     }))
 )
 
-const JsonifiableUser2 = Jsonifiable(User)(S.Struct({
-    ...User.fields,
-    id: S.BigInt,
-}))
-
 
 const user1 = new User({ id: -1n, role: "BasicUser" })
 reaction(() => user1.id, id => console.log(`user1 id changed: ${ id }`))