diff --git a/src/compiler/core.ts b/src/compiler/core.ts
index a3910334286..7f165a171f8 100644
--- a/src/compiler/core.ts
+++ b/src/compiler/core.ts
@@ -992,11 +992,15 @@ namespace ts {
     }
 
     /**
-     * Performs a binary search, finding the index at which 'value' occurs in 'array'.
+     * Performs a binary search, finding the index at which `value` occurs in `array`.
      * If no such index is found, returns the 2's-complement of first index at which
-     * number[index] exceeds number.
+     * `array[index]` exceeds `value`.
      * @param array A sorted array whose first element must be no larger than number
-     * @param number The value to be searched for in the array.
+     * @param value The value to be searched for in the array.
+     * @param keySelector A callback used to select the search key from `value` and each element of
+     * `array`.
+     * @param keyComparer A callback used to compare two keys in a sorted array.
+     * @param offset An offset into `array` at which to start the search.
      */
     export function binarySearch<T, U>(array: ReadonlyArray<T>, value: T, keySelector: (v: T) => U, keyComparer: Comparer<U>, offset?: number): number {
         if (!array || array.length === 0) {