diff --git a/packages/firebase_messaging/firebase_messaging/ios/firebase_messaging/Sources/firebase_messaging/FLTFirebaseMessagingPlugin.m b/packages/firebase_messaging/firebase_messaging/ios/firebase_messaging/Sources/firebase_messaging/FLTFirebaseMessagingPlugin.m
index 74bbcb5142e0..d62ffdc0dc2f 100644
--- a/packages/firebase_messaging/firebase_messaging/ios/firebase_messaging/Sources/firebase_messaging/FLTFirebaseMessagingPlugin.m
+++ b/packages/firebase_messaging/firebase_messaging/ios/firebase_messaging/Sources/firebase_messaging/FLTFirebaseMessagingPlugin.m
@@ -992,7 +992,7 @@ + (NSDictionary *)remoteMessageUserInfoToDict:(NSDictionary *)userInfo {
     if (apsDict[@"sound"] != nil) {
       if ([apsDict[@"sound"] isKindOfClass:[NSString class]]) {
         // message.notification.apple.sound
-        notification[@"sound"] = @{
+        notificationIOS[@"sound"] = @{
           @"name" : apsDict[@"sound"],
           @"critical" : @NO,
           @"volume" : @1,