diff --git a/index.d.ts b/index.d.ts
index 5e8bfeea961913e3b533a50e88d232fb644b149f..bf7f44320929c211e096ad07e67c007a6cba99fa 100644
--- a/index.d.ts
+++ b/index.d.ts
@@ -43,7 +43,7 @@ declare module "react-native-fcm" {
         body: string;
         icon?: string;
         vibrate?: number;
-        sound?: boolean;
+        sound?: string;
         big_text?: string;
         large_icon?: string;
         priority?: string