diff --git a/packages/amplify-appsync-simulator/src/__tests__/velocity/value-mapper/map.test.ts b/packages/amplify-appsync-simulator/src/__tests__/velocity/value-mapper/map.test.ts
index 2cfbbcb56e9..6b566292e84 100644
--- a/packages/amplify-appsync-simulator/src/__tests__/velocity/value-mapper/map.test.ts
+++ b/packages/amplify-appsync-simulator/src/__tests__/velocity/value-mapper/map.test.ts
@@ -1,4 +1,7 @@
+import { JavaArray } from './../../../velocity/value-mapper/array';
 import { JavaMap } from '../../../velocity/value-mapper/map';
+import { JavaString } from '../../../velocity/value-mapper/string';
+import { map as mapper } from '../../../velocity/value-mapper/mapper';
 
 describe('JavaMap', () => {
   let identityMapper = jest.fn().mockImplementation(val => val);
@@ -36,7 +39,10 @@ describe('JavaMap', () => {
   it('entrySet', () => {
     const obj = { foo: 'Foo Value', bar: 'Bar Value' };
     const map = new JavaMap(obj, identityMapper);
-    expect(map.entrySet().toJSON()).toEqual([{ key: 'foo', value: 'Foo Value' }, { key: 'bar', value: 'Bar Value' }]);
+    expect(map.entrySet().toJSON()).toEqual([
+      { key: 'foo', value: 'Foo Value' },
+      { key: 'bar', value: 'Bar Value' },
+    ]);
   });
 
   it('equal', () => {
@@ -66,6 +72,12 @@ describe('JavaMap', () => {
     expect(map.keySet().toJSON()).toEqual(['foo', 'bar']);
   });
 
+  it('keySet returns a JavaArray with each element of type JavaString', () => {
+    const obj = { foo: 'Foo Value', bar: 'Bar Value' };
+    const map = new JavaMap(obj, identityMapper);
+    expect(map.keySet()).toEqual(new JavaArray([new JavaString('foo'), new JavaString('bar')], mapper));
+  });
+
   it('put', () => {
     const map = new JavaMap({}, identityMapper);
     map.put('foo', 'Foo Value');
diff --git a/packages/amplify-appsync-simulator/src/__tests__/velocity/value-mapper/string.test.ts b/packages/amplify-appsync-simulator/src/__tests__/velocity/value-mapper/string.test.ts
index 2867b7e9df7..3657df1f5ad 100644
--- a/packages/amplify-appsync-simulator/src/__tests__/velocity/value-mapper/string.test.ts
+++ b/packages/amplify-appsync-simulator/src/__tests__/velocity/value-mapper/string.test.ts
@@ -1,4 +1,4 @@
-import { JavaString, toJavaString } from '../../../velocity/value-mapper/string';
+import { JavaString } from '../../../velocity/value-mapper/string';
 
 describe('JavaString', () => {
   it('replaceAll', () => {
@@ -131,8 +131,4 @@ describe('JavaString', () => {
     const str4 = new JavaString('foo bar      ');
     expect(str4.trim().toString()).toEqual('foo bar');
   });
-  it('toJavaString', () => {
-    const str = toJavaString('foo bar');
-    expect(str instanceof JavaString).toBeTruthy();
-  });
 });
diff --git a/packages/amplify-appsync-simulator/src/velocity/value-mapper/array.ts b/packages/amplify-appsync-simulator/src/velocity/value-mapper/array.ts
index 9936b4aed4c..912c20926e4 100644
--- a/packages/amplify-appsync-simulator/src/velocity/value-mapper/array.ts
+++ b/packages/amplify-appsync-simulator/src/velocity/value-mapper/array.ts
@@ -1,4 +1,3 @@
-import { JavaString } from './string';
 import { toJSON } from './to-json';
 
 export class JavaArray extends Array<any> {
@@ -8,13 +7,6 @@ export class JavaArray extends Array<any> {
       // splice sends a single object
       values = [values];
     }
-    values = values.map(value => {
-        if (typeof value === 'string' && !((value as any) instanceof JavaString)) {
-          return new JavaString(value);
-        }
-          return value;
-      });
-
     if (values.length !== 1) {
       super(...values);
     } else {
diff --git a/packages/amplify-appsync-simulator/src/velocity/value-mapper/map.ts b/packages/amplify-appsync-simulator/src/velocity/value-mapper/map.ts
index d075fa022b0..5a2e7528759 100644
--- a/packages/amplify-appsync-simulator/src/velocity/value-mapper/map.ts
+++ b/packages/amplify-appsync-simulator/src/velocity/value-mapper/map.ts
@@ -1,5 +1,6 @@
 import { JavaArray } from './array';
 import { toJSON } from './to-json';
+import { map } from './mapper';
 
 export class JavaMap {
   private map: Map<string, any>;
@@ -56,7 +57,7 @@ export class JavaMap {
   }
 
   keySet() {
-    return new JavaArray(Array.from(this.map.keys()), this.mapper);
+    return map(Array.from(this.map.keys()));
   }
 
   put(key, value) {
diff --git a/packages/amplify-appsync-simulator/src/velocity/value-mapper/string.ts b/packages/amplify-appsync-simulator/src/velocity/value-mapper/string.ts
index b966b896a75..f07fd90f119 100644
--- a/packages/amplify-appsync-simulator/src/velocity/value-mapper/string.ts
+++ b/packages/amplify-appsync-simulator/src/velocity/value-mapper/string.ts
@@ -107,7 +107,3 @@ export class JavaString {
     return this.value && this.value.length;
   }
 }
-/**
- * Mapper function to convert string to JavaString
- */
-export const toJavaString = (value: string): JavaString => new JavaString(value);