diff --git a/src/lib/es5.d.ts b/src/lib/es5.d.ts
index cf95c473240fe..2ed5de3627404 100644
--- a/src/lib/es5.d.ts
+++ b/src/lib/es5.d.ts
@@ -4284,6 +4284,7 @@ declare namespace Intl {
         style?: string;
         currency?: string;
         currencyDisplay?: string;
+        currencySign?: string;
         useGrouping?: boolean;
         minimumIntegerDigits?: number;
         minimumFractionDigits?: number;