diff --git a/src/helpers.ts b/src/helpers.ts
index f8219b3544d..c3a849d6a18 100644
--- a/src/helpers.ts
+++ b/src/helpers.ts
@@ -17,7 +17,7 @@ export class Helpers {
    * @method faker.helpers.randomize
    * @param array
    */
-  randomize<T = string>(array: T[] = ['a', 'b', 'c'] as unknown as T[]): T {
+  randomize<T = string>(array: ReadonlyArray<T> = ['a', 'b', 'c'] as unknown as ReadonlyArray<T>): T {
     return this.faker.random.arrayElement(array);
   }
 
diff --git a/src/random.ts b/src/random.ts
index d460b4e36ca..8414134a84a 100644
--- a/src/random.ts
+++ b/src/random.ts
@@ -72,7 +72,7 @@ export class Random {
    * @method faker.random.arrayElement
    * @param array
    */
-  arrayElement<T = string>(array: T[] = ['a', 'b', 'c'] as unknown as T[]): T {
+  arrayElement<T = string>(array: ReadonlyArray<T> = ['a', 'b', 'c'] as unknown as ReadonlyArray<T>): T {
     const r = this.faker.datatype.number({ max: array.length - 1 });
     return array[r];
   }
@@ -85,7 +85,7 @@ export class Random {
    * @param count number of elements to pick
    */
   arrayElements<T>(
-    array: T[] = ['a', 'b', 'c'] as unknown as T[],
+    array: ReadonlyArray<T> = ['a', 'b', 'c'] as unknown as ReadonlyArray<T>,
     count?: number
   ): T[] {
     if (typeof count !== 'number') {