diff --git a/src/lib/es5.d.ts b/src/lib/es5.d.ts
index 0d1481dd7d2..2594344decc 100644
--- a/src/lib/es5.d.ts
+++ b/src/lib/es5.d.ts
@@ -12,7 +12,7 @@ declare var Infinity: number;
 declare function eval(x: string): any;
 
 /**
-  * Converts A string to an integer.
+  * Converts a string to an integer.
   * @param s A string to convert into a number.
   * @param radix A value between 2 and 36 that specifies the base of the number in numString.
   * If this argument is not supplied, strings with a prefix of '0x' are considered hexadecimal.