diff --git a/tests/baselines/reference/constAssertions.js b/tests/baselines/reference/constAssertions.js
index 3173e2bf92a..8da3b3e5b51 100644
--- a/tests/baselines/reference/constAssertions.js
+++ b/tests/baselines/reference/constAssertions.js
@@ -258,6 +258,7 @@ declare let o2: {
     readonly d: () => void;
 };
 declare let o3: {
+    readonly [x: string]: 10 | 1 | 2 | 3 | 20 | (() => void) | 4;
     readonly a: 1;
     readonly b: 2;
     readonly c: 3;
diff --git a/tests/baselines/reference/constAssertions.types b/tests/baselines/reference/constAssertions.types
index 0668c0235aa..a042eb17466 100644
--- a/tests/baselines/reference/constAssertions.types
+++ b/tests/baselines/reference/constAssertions.types
@@ -202,9 +202,9 @@ let o2 = { a: 1, 'b': 2, ['c']: 3, d() {}, ['e' + '']: 4 } as const;
 >4 : 4
 
 let o3 = { ...o1, ...o2 } as const;
->o3 : { readonly a: 1; readonly b: 2; readonly c: 3; readonly d: () => void; readonly x: 10; readonly y: 20; }
->{ ...o1, ...o2 } as const : { readonly a: 1; readonly b: 2; readonly c: 3; readonly d: () => void; readonly x: 10; readonly y: 20; }
->{ ...o1, ...o2 } : { readonly a: 1; readonly b: 2; readonly c: 3; readonly d: () => void; readonly x: 10; readonly y: 20; }
+>o3 : { readonly [x: string]: 10 | 1 | 2 | 3 | 20 | (() => void) | 4; readonly a: 1; readonly b: 2; readonly c: 3; readonly d: () => void; readonly x: 10; readonly y: 20; }
+>{ ...o1, ...o2 } as const : { readonly [x: string]: 10 | 1 | 2 | 3 | 20 | (() => void) | 4; readonly a: 1; readonly b: 2; readonly c: 3; readonly d: () => void; readonly x: 10; readonly y: 20; }
+>{ ...o1, ...o2 } : { readonly [x: string]: 10 | 1 | 2 | 3 | 20 | (() => void) | 4; readonly a: 1; readonly b: 2; readonly c: 3; readonly d: () => void; readonly x: 10; readonly y: 20; }
 >o1 : { readonly x: 10; readonly y: 20; }
 >o2 : { readonly [x: string]: 1 | 2 | 3 | (() => void) | 4; readonly a: 1; readonly b: 2; readonly c: 3; readonly d: () => void; }
 
diff --git a/tests/baselines/reference/objectSpreadComputedProperty.types b/tests/baselines/reference/objectSpreadComputedProperty.types
index ce61004aa04..16bd8a6de0a 100644
--- a/tests/baselines/reference/objectSpreadComputedProperty.types
+++ b/tests/baselines/reference/objectSpreadComputedProperty.types
@@ -17,24 +17,24 @@ function f() {
 >a : any
 
     const o1 = { ...{}, [n]: n };
->o1 : {}
->{ ...{}, [n]: n } : {}
+>o1 : { [x: number]: number; }
+>{ ...{}, [n]: n } : { [x: number]: number; }
 >{} : {}
 >[n] : number
 >n : number
 >n : number
 
     const o2 = { ...{}, [a]: n };
->o2 : {}
->{ ...{}, [a]: n } : {}
+>o2 : { [x: number]: number; }
+>{ ...{}, [a]: n } : { [x: number]: number; }
 >{} : {}
 >[a] : number
 >a : any
 >n : number
 
     const o3 = { [a]: n, ...{}, [n]: n, ...{}, [m]: m };
->o3 : {}
->{ [a]: n, ...{}, [n]: n, ...{}, [m]: m } : {}
+>o3 : { [x: number]: number; }
+>{ [a]: n, ...{}, [n]: n, ...{}, [m]: m } : { [x: number]: number; }
 >[a] : number
 >a : any
 >n : number
diff --git a/tests/baselines/reference/useBeforeDeclaration_propertyAssignment.types b/tests/baselines/reference/useBeforeDeclaration_propertyAssignment.types
index a6c6e1faceb..15079f94f2c 100644
--- a/tests/baselines/reference/useBeforeDeclaration_propertyAssignment.types
+++ b/tests/baselines/reference/useBeforeDeclaration_propertyAssignment.types
@@ -5,8 +5,8 @@ export class C {
 >C : C
 
     public a =  { b: this.b, ...this.c, [this.b]: `${this.c}`};
->a : { c: number; b: number; }
->{ b: this.b, ...this.c, [this.b]: `${this.c}`} : { c: number; b: number; }
+>a : { [x: number]: string; c: number; b: number; }
+>{ b: this.b, ...this.c, [this.b]: `${this.c}`} : { [x: number]: string; c: number; b: number; }
 >b : number
 >this.b : number
 >this : this