diff --git a/tests/cases/conformance/types/mapped/mappedTypeModifiers.ts b/tests/cases/conformance/types/mapped/mappedTypeModifiers.ts
index 1e76c5b745284..30aa652f0d9c0 100644
--- a/tests/cases/conformance/types/mapped/mappedTypeModifiers.ts
+++ b/tests/cases/conformance/types/mapped/mappedTypeModifiers.ts
@@ -1,85 +1,71 @@
 // @strictNullChecks: true
 
 type T = { a: number, b: string };
-type TU = { a: number | undefined, b: string | undefined };
 type TP = { a?: number, b?: string };
 type TR = { readonly a: number, readonly b: string };
 type TPR = { readonly a?: number, readonly b?: string };
 
-// Validate they all have the same keys
 var v00: "a" | "b";
 var v00: keyof T;
-var v00: keyof TU;
 var v00: keyof TP;
 var v00: keyof TR;
 var v00: keyof TPR;
 
-// Validate that non-isomorphic mapped types strip modifiers
 var v01: T;
-var v01: Pick<TR, keyof T>;
-var v01: Pick<Readonly<T>, keyof T>;
+var v01: { [P in keyof T]: T[P] };
+var v01: Pick<T, keyof T>;
+var v01: Pick<Pick<T, keyof T>, keyof T>;
 
-// Validate that non-isomorphic mapped types strip modifiers
-var v02: TU;
+var v02: TP;
+var v02: { [P in keyof T]?: T[P] };
+var v02: Partial<T>;
 var v02: Pick<TP, keyof T>;
-var v02: Pick<TPR, keyof T>;
-var v02: Pick<Partial<T>, keyof T>;
-var v02: Pick<Partial<Readonly<T>>, keyof T>;
 
-// Validate that isomorphic mapped types preserve optional modifier
-var v03: TP;
-var v03: Partial<T>;
+var v03: TR;
+var v03: { readonly [P in keyof T]: T[P] };
+var v03: Readonly<T>;
+var v03: Pick<TR, keyof T>;
 
-// Validate that isomorphic mapped types preserve readonly modifier
-var v04: TR;
-var v04: Readonly<T>;
-
-// Validate that isomorphic mapped types preserve both partial and readonly modifiers
-var v05: TPR;
-var v05: Partial<TR>;
-var v05: Readonly<TP>;
-var v05: Partial<Readonly<T>>;
-var v05: Readonly<Partial<T>>;
+var v04: TPR;
+var v04: { readonly [P in keyof T]?: T[P] };
+var v04: Partial<TR>;
+var v04: Readonly<TP>;
+var v04: Partial<Readonly<T>>;
+var v04: Readonly<Partial<T>>;
+var v04: Pick<TPR, keyof T>;
 
 type Boxified<T> = { [P in keyof T]: { x: T[P] } };
 
 type B = { a: { x: number }, b: { x: string } };
-type BU = { a: { x: number } | undefined, b: { x: string } | undefined };
 type BP = { a?: { x: number }, b?: { x: string } };
 type BR = { readonly a: { x: number }, readonly b: { x: string } };
 type BPR = { readonly a?: { x: number }, readonly b?: { x: string } };
 
-// Validate they all have the same keys
 var b00: "a" | "b";
 var b00: keyof B;
-var b00: keyof BU;
 var b00: keyof BP;
 var b00: keyof BR;
 var b00: keyof BPR;
 
-// Validate that non-isomorphic mapped types strip modifiers
 var b01: B;
-var b01: Pick<BR, keyof B>;
-var b01: Pick<Readonly<BR>, keyof B>;
+var b01: { [P in keyof B]: B[P] };
+var b01: Pick<B, keyof B>;
+var b01: Pick<Pick<B, keyof B>, keyof B>;
 
-// Validate that non-isomorphic mapped types strip modifiers
-var b02: BU;
+var b02: BP;
+var b02: { [P in keyof B]?: B[P] };
+var b02: Partial<B>;
 var b02: Pick<BP, keyof B>;
-var b02: Pick<BPR, keyof B>;
-var b02: Pick<Partial<B>, keyof B>;
-var b02: Pick<Partial<Readonly<B>>, keyof B>;
-
-// Validate that isomorphic mapped types preserve optional modifier
-var b03: BP;
-var b03: Partial<B>;
 
-// Validate that isomorphic mapped types preserve readonly modifier
-var b04: BR;
-var b04: Readonly<B>;
+var b03: BR;
+var b03: { readonly [P in keyof B]: B[P] };
+var b03: Readonly<B>;
+var b03: Pick<BR, keyof B>;
 
-// Validate that isomorphic mapped types preserve both partial and readonly modifiers
-var b05: BPR;
-var b05: Partial<BR>;
-var b05: Readonly<BP>;
-var b05: Partial<Readonly<B>>;
-var b05: Readonly<Partial<B>>;
\ No newline at end of file
+var b04: BPR;
+var b04: { readonly [P in keyof B]?: B[P] };
+var b04: Partial<BR>;
+var b04: Readonly<BP>;
+var b04: Partial<Readonly<B>>;
+var b04: Readonly<Partial<B>>;
+var b04: Pick<BPR, keyof B>;
\ No newline at end of file