diff --git a/src/lib/es5.d.ts b/src/lib/es5.d.ts
index 0563e7eb8e6..82cc372ee9a 100644
--- a/src/lib/es5.d.ts
+++ b/src/lib/es5.d.ts
@@ -4311,12 +4311,21 @@ interface Float64Array {
     sort(compareFn?: (a: number, b: number) => number): this;
 
     /**
+     * Gets a new Float64Array view of the ArrayBuffer store for this array, referencing the elements
      * at begin, inclusive, up to end, exclusive.
      * @param begin The index of the beginning of the array.
      * @param end The index of the end of the array.
      */
     subarray(begin?: number, end?: number): Float64Array;
 
+    /**
+     * Converts a number to a string by using the current locale.
+     */
+    toLocaleString(): string;
+
+    /**
+     * Returns a string representation of an array.
+     */
     toString(): string;
 
     /** Returns the primitive value of the specified object. */