diff --git a/src/lib/es2020.intl.d.ts b/src/lib/es2020.intl.d.ts
index ab43357d933e6..eb8ac542d8b64 100644
--- a/src/lib/es2020.intl.d.ts
+++ b/src/lib/es2020.intl.d.ts
@@ -261,4 +261,12 @@ declare namespace Intl {
             options?: RelativeTimeFormatOptions,
         ): BCP47LanguageTag[];
     };
+
+    interface NumberFormatOptions {
+        notation?: string;
+    }
+
+    interface ResolvedNumberFormatOptions {
+        notation?: string;
+    }
 }
diff --git a/tests/lib/lib.d.ts b/tests/lib/lib.d.ts
index 9edbdec2b1b13..5bbe688910fa9 100644
--- a/tests/lib/lib.d.ts
+++ b/tests/lib/lib.d.ts
@@ -3898,6 +3898,7 @@ declare module Intl {
         maximumFractionDigits?: number;
         minimumSignificantDigits?: number;
         maximumSignificantDigits?: number;
+        notation?: string;
     }
 
     interface ResolvedNumberFormatOptions {
@@ -3912,6 +3913,7 @@ declare module Intl {
         minimumSignificantDigits?: number;
         maximumSignificantDigits?: number;
         useGrouping: boolean;
+        notation?: string;
     }
 
     interface NumberFormat {