diff --git a/packages/pigeon/example/README.md b/packages/pigeon/example/README.md
index 6f810b674b8..bd5e4bd116a 100644
--- a/packages/pigeon/example/README.md
+++ b/packages/pigeon/example/README.md
@@ -62,7 +62,7 @@ class MessageData {
   String? name;
   String? description;
   Code code;
-  Map<String?, String?> data;
+  Map<String, String> data;
 }
 
 @HostApi()
@@ -103,7 +103,7 @@ Future<int> add(int a, int b) async {
 Future<bool> sendMessage(String messageText) {
   final MessageData message = MessageData(
     code: Code.one,
-    data: <String?, String?>{'header': 'this is a header'},
+    data: <String, String>{'header': 'this is a header'},
     description: 'uri text',
   );
   try {
diff --git a/packages/pigeon/example/app/android/app/src/main/kotlin/dev/flutter/pigeon_example_app/Messages.g.kt b/packages/pigeon/example/app/android/app/src/main/kotlin/dev/flutter/pigeon_example_app/Messages.g.kt
index cc56f5bb3b2..c6b32713ebf 100644
--- a/packages/pigeon/example/app/android/app/src/main/kotlin/dev/flutter/pigeon_example_app/Messages.g.kt
+++ b/packages/pigeon/example/app/android/app/src/main/kotlin/dev/flutter/pigeon_example_app/Messages.g.kt
@@ -62,14 +62,14 @@ data class MessageData(
     val name: String? = null,
     val description: String? = null,
     val code: Code,
-    val data: Map<String?, String?>
+    val data: Map<String, String>
 ) {
   companion object {
     fun fromList(pigeonVar_list: List<Any?>): MessageData {
       val name = pigeonVar_list[0] as String?
       val description = pigeonVar_list[1] as String?
       val code = pigeonVar_list[2] as Code
-      val data = pigeonVar_list[3] as Map<String?, String?>
+      val data = pigeonVar_list[3] as Map<String, String>
       return MessageData(name, description, code, data)
     }
   }
diff --git a/packages/pigeon/example/app/ios/Runner/Messages.g.swift b/packages/pigeon/example/app/ios/Runner/Messages.g.swift
index d85e3ca01bc..b42c8a41a1d 100644
--- a/packages/pigeon/example/app/ios/Runner/Messages.g.swift
+++ b/packages/pigeon/example/app/ios/Runner/Messages.g.swift
@@ -83,14 +83,14 @@ struct MessageData {
   var name: String? = nil
   var description: String? = nil
   var code: Code
-  var data: [String?: String?]
+  var data: [String: String]
 
   // swift-format-ignore: AlwaysUseLowerCamelCase
   static func fromList(_ pigeonVar_list: [Any?]) -> MessageData? {
     let name: String? = nilOrValue(pigeonVar_list[0])
     let description: String? = nilOrValue(pigeonVar_list[1])
     let code = pigeonVar_list[2] as! Code
-    let data = pigeonVar_list[3] as! [String?: String?]
+    let data = pigeonVar_list[3] as! [String: String]
 
     return MessageData(
       name: name,
diff --git a/packages/pigeon/example/app/lib/main.dart b/packages/pigeon/example/app/lib/main.dart
index 48138f9e950..cc158abe0c1 100644
--- a/packages/pigeon/example/app/lib/main.dart
+++ b/packages/pigeon/example/app/lib/main.dart
@@ -73,7 +73,7 @@ class _MyHomePageState extends State<MyHomePage> {
   Future<bool> sendMessage(String messageText) {
     final MessageData message = MessageData(
       code: Code.one,
-      data: <String?, String?>{'header': 'this is a header'},
+      data: <String, String>{'header': 'this is a header'},
       description: 'uri text',
     );
     try {
diff --git a/packages/pigeon/example/app/lib/src/messages.g.dart b/packages/pigeon/example/app/lib/src/messages.g.dart
index 0a95e8bf5f1..33080952576 100644
--- a/packages/pigeon/example/app/lib/src/messages.g.dart
+++ b/packages/pigeon/example/app/lib/src/messages.g.dart
@@ -48,7 +48,7 @@ class MessageData {
 
   Code code;
 
-  Map<String?, String?> data;
+  Map<String, String> data;
 
   Object encode() {
     return <Object?>[
@@ -65,7 +65,7 @@ class MessageData {
       name: result[0] as String?,
       description: result[1] as String?,
       code: result[2]! as Code,
-      data: (result[3] as Map<Object?, Object?>?)!.cast<String?, String?>(),
+      data: (result[3] as Map<Object?, Object?>?)!.cast<String, String>(),
     );
   }
 }
diff --git a/packages/pigeon/example/app/pigeons/messages.dart b/packages/pigeon/example/app/pigeons/messages.dart
index 8c18cc87e81..2112fed9637 100644
--- a/packages/pigeon/example/app/pigeons/messages.dart
+++ b/packages/pigeon/example/app/pigeons/messages.dart
@@ -40,7 +40,7 @@ class MessageData {
   String? name;
   String? description;
   Code code;
-  Map<String?, String?> data;
+  Map<String, String> data;
 }
 
 @HostApi()