diff --git a/modules/openapi-generator/src/main/resources/dart2/api_client.mustache b/modules/openapi-generator/src/main/resources/dart2/api_client.mustache
index e6e6b07771..09edf0a827 100644
--- a/modules/openapi-generator/src/main/resources/dart2/api_client.mustache
+++ b/modules/openapi-generator/src/main/resources/dart2/api_client.mustache
@@ -49,6 +49,12 @@ class ApiClient {
      _defaultHeaderMap[key] = value;
   }
 
+  Map<String,String> get defaultHeaderMap => _defaultHeaderMap;
+  /// returns an unmodifiable view of the authentications, since none should be added
+  /// nor deleted
+  Map<String, Authentication> get authentications =>
+      Map.unmodififiable(_authentications);
+
   dynamic deserialize(String json, String targetType, {bool growable}) {
     // Remove all spaces.  Necessary for reg expressions as well.
     targetType = targetType.replaceAll(' ', '');
diff --git a/samples/client/petstore/dart2/petstore_client_lib/lib/api_client.dart b/samples/client/petstore/dart2/petstore_client_lib/lib/api_client.dart
index 79394cc833..e9fe382f91 100644
--- a/samples/client/petstore/dart2/petstore_client_lib/lib/api_client.dart
+++ b/samples/client/petstore/dart2/petstore_client_lib/lib/api_client.dart
@@ -42,6 +42,12 @@ class ApiClient {
      _defaultHeaderMap[key] = value;
   }
 
+  Map<String,String> get defaultHeaderMap => _defaultHeaderMap;
+  /// returns an unmodifiable view of the authentications, since none should be added
+  /// nor deleted
+  Map<String, Authentication> get authentications =>
+      Map.unmodififiable(_authentications);
+
   dynamic deserialize(String json, String targetType, {bool growable}) {
     // Remove all spaces.  Necessary for reg expressions as well.
     targetType = targetType.replaceAll(' ', '');
diff --git a/samples/openapi3/client/petstore/dart2/petstore_client_lib/lib/api_client.dart b/samples/openapi3/client/petstore/dart2/petstore_client_lib/lib/api_client.dart
index 79394cc833..e9fe382f91 100644
--- a/samples/openapi3/client/petstore/dart2/petstore_client_lib/lib/api_client.dart
+++ b/samples/openapi3/client/petstore/dart2/petstore_client_lib/lib/api_client.dart
@@ -42,6 +42,12 @@ class ApiClient {
      _defaultHeaderMap[key] = value;
   }
 
+  Map<String,String> get defaultHeaderMap => _defaultHeaderMap;
+  /// returns an unmodifiable view of the authentications, since none should be added
+  /// nor deleted
+  Map<String, Authentication> get authentications =>
+      Map.unmodififiable(_authentications);
+
   dynamic deserialize(String json, String targetType, {bool growable}) {
     // Remove all spaces.  Necessary for reg expressions as well.
     targetType = targetType.replaceAll(' ', '');
diff --git a/samples/openapi3/client/petstore/dart2/petstore_client_lib_fake/lib/api_client.dart b/samples/openapi3/client/petstore/dart2/petstore_client_lib_fake/lib/api_client.dart
index 22d45db938..ef90645965 100644
--- a/samples/openapi3/client/petstore/dart2/petstore_client_lib_fake/lib/api_client.dart
+++ b/samples/openapi3/client/petstore/dart2/petstore_client_lib_fake/lib/api_client.dart
@@ -45,6 +45,12 @@ class ApiClient {
      _defaultHeaderMap[key] = value;
   }
 
+  Map<String,String> get defaultHeaderMap => _defaultHeaderMap;
+  /// returns an unmodifiable view of the authentications, since none should be added
+  /// nor deleted
+  Map<String, Authentication> get authentications =>
+      Map.unmodififiable(_authentications);
+
   dynamic deserialize(String json, String targetType, {bool growable}) {
     // Remove all spaces.  Necessary for reg expressions as well.
     targetType = targetType.replaceAll(' ', '');