diff --git a/index.d.ts b/index.d.ts
index 855de54f0a26603f5f56362f5903862a9231bbe1..79fa43588a7b023e3d9d88187afc8c21712d561c 100644
--- a/index.d.ts
+++ b/index.d.ts
@@ -42,7 +42,7 @@ declare module "react-native-fcm" {
         body: string;
         icon?: string;
         vibrate?: number;
-        sound?: boolean;
+        sound?: string;
         big_text?: string;
         large_icon?: string;
         priority?: string