diff --git a/notification_dispatcher/CHANGELOG.md b/notification_dispatcher/CHANGELOG.md
index a526ded..de89674 100644
--- a/notification_dispatcher/CHANGELOG.md
+++ b/notification_dispatcher/CHANGELOG.md
@@ -13,6 +13,7 @@
 
 ### Breaking
 - Removed `NotificationDispatcher.observers`.
+- Removed `NotificationMessage` in favour of a simple `Map<String, dynamic>`.
 
 ### Documentation
 - Tidied up documentation.
diff --git a/notification_dispatcher/lib/src/notification_dispatcher.dart b/notification_dispatcher/lib/src/notification_dispatcher.dart
index fe11fde..5268d1b 100644
--- a/notification_dispatcher/lib/src/notification_dispatcher.dart
+++ b/notification_dispatcher/lib/src/notification_dispatcher.dart
@@ -1,7 +1,5 @@
 import 'typedefs.dart';
 
-part 'notification_message.dart';
-
 /// Passes notifications around to registered observers. The class comes with a
 /// default instance named [NotificationDispatcher.instance].
 final class NotificationDispatcher {
@@ -54,12 +52,11 @@ final class NotificationDispatcher {
   /// running all callbacks registered with [name].
   /// {@endtemplate}
   void post({
-    Object? sender,
     required String name,
-    Map<String, dynamic>? info,
+    NotificationMessage? info,
   }) {
     for (final callback in _observers.values.toList()) {
-      callback[name]?.call(NotificationMessage._(sender: sender, info: info));
+      callback[name]?.call(info);
     }
 
     return;
diff --git a/notification_dispatcher/lib/src/notification_message.dart b/notification_dispatcher/lib/src/notification_message.dart
deleted file mode 100644
index 05ef2e2..0000000
--- a/notification_dispatcher/lib/src/notification_message.dart
+++ /dev/null
@@ -1,15 +0,0 @@
-part of 'notification_dispatcher.dart';
-
-/// The class used to store a notification's payload.
-final class NotificationMessage {
-  const NotificationMessage._({
-    required this.sender,
-    required this.info,
-  });
-
-  /// The sender posting the notification
-  final Object? sender;
-
-  /// The info being posted with the notification.
-  final Map<String, dynamic>? info;
-}
diff --git a/notification_dispatcher/lib/src/typedefs.dart b/notification_dispatcher/lib/src/typedefs.dart
index b89fbf1..64a3934 100644
--- a/notification_dispatcher/lib/src/typedefs.dart
+++ b/notification_dispatcher/lib/src/typedefs.dart
@@ -1,4 +1,5 @@
-import 'notification_dispatcher.dart';
-
 /// Callback signature when receiving a notification.
-typedef NotificationCallback = void Function(NotificationMessage message);
+typedef NotificationCallback = void Function(NotificationMessage? message);
+
+/// The message being posted/received.
+typedef NotificationMessage = Map<String, dynamic>;