diff --git a/modules/openapi-generator/src/main/resources/dart/libraries/dio/serialization/built_value/serializers.mustache b/modules/openapi-generator/src/main/resources/dart/libraries/dio/serialization/built_value/serializers.mustache
index aa49d9aef9e..d59a148bae9 100644
--- a/modules/openapi-generator/src/main/resources/dart/libraries/dio/serialization/built_value/serializers.mustache
+++ b/modules/openapi-generator/src/main/resources/dart/libraries/dio/serialization/built_value/serializers.mustache
@@ -38,8 +38,8 @@ Serializers serializers = (_$serializers.toBuilder(){{#builtValueSerializers}}
       ..add(const OffsetDateSerializer())
       ..add(const OffsetDateTimeSerializer()){{/useDateLibTimeMachine}}{{#useDateLibCore}}
       ..add(const DateSerializer())
-      ..add(Iso8601DateTimeSerializer())){{/useDateLibCore}}
-    .build();
+      ..add(Iso8601DateTimeSerializer()){{/useDateLibCore}}
+    ).build();
 
 Serializers standardSerializers =
     (serializers.toBuilder()..addPlugin(StandardJsonPlugin())).build();
diff --git a/samples/openapi3/client/petstore/dart-dio/oneof/lib/src/serializers.dart b/samples/openapi3/client/petstore/dart-dio/oneof/lib/src/serializers.dart
index ddb1d66a1f5..9c32c391086 100644
--- a/samples/openapi3/client/petstore/dart-dio/oneof/lib/src/serializers.dart
+++ b/samples/openapi3/client/petstore/dart-dio/oneof/lib/src/serializers.dart
@@ -29,8 +29,8 @@ Serializers serializers = (_$serializers.toBuilder()
       ..add(const OneOfSerializer())
       ..add(const AnyOfSerializer())
       ..add(const DateSerializer())
-      ..add(Iso8601DateTimeSerializer()))
-    .build();
+      ..add(Iso8601DateTimeSerializer())
+    ).build();
 
 Serializers standardSerializers =
     (serializers.toBuilder()..addPlugin(StandardJsonPlugin())).build();
diff --git a/samples/openapi3/client/petstore/dart-dio/oneof_polymorphism_and_inheritance/lib/src/serializers.dart b/samples/openapi3/client/petstore/dart-dio/oneof_polymorphism_and_inheritance/lib/src/serializers.dart
index 14964c349ad..60a5a39c4cb 100644
--- a/samples/openapi3/client/petstore/dart-dio/oneof_polymorphism_and_inheritance/lib/src/serializers.dart
+++ b/samples/openapi3/client/petstore/dart-dio/oneof_polymorphism_and_inheritance/lib/src/serializers.dart
@@ -68,8 +68,8 @@ Serializers serializers = (_$serializers.toBuilder()
       ..add(const OneOfSerializer())
       ..add(const AnyOfSerializer())
       ..add(const DateSerializer())
-      ..add(Iso8601DateTimeSerializer()))
-    .build();
+      ..add(Iso8601DateTimeSerializer())
+    ).build();
 
 Serializers standardSerializers =
     (serializers.toBuilder()..addPlugin(StandardJsonPlugin())).build();
diff --git a/samples/openapi3/client/petstore/dart-dio/oneof_primitive/lib/src/serializers.dart b/samples/openapi3/client/petstore/dart-dio/oneof_primitive/lib/src/serializers.dart
index cbd8870dc67..96edb8b274c 100644
--- a/samples/openapi3/client/petstore/dart-dio/oneof_primitive/lib/src/serializers.dart
+++ b/samples/openapi3/client/petstore/dart-dio/oneof_primitive/lib/src/serializers.dart
@@ -27,8 +27,8 @@ Serializers serializers = (_$serializers.toBuilder()
       ..add(const OneOfSerializer())
       ..add(const AnyOfSerializer())
       ..add(const DateSerializer())
-      ..add(Iso8601DateTimeSerializer()))
-    .build();
+      ..add(Iso8601DateTimeSerializer())
+    ).build();
 
 Serializers standardSerializers =
     (serializers.toBuilder()..addPlugin(StandardJsonPlugin())).build();
diff --git a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake/lib/src/serializers.dart b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake/lib/src/serializers.dart
index 98ec8cd5dfc..9ec6472d69e 100644
--- a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake/lib/src/serializers.dart
+++ b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake/lib/src/serializers.dart
@@ -161,8 +161,8 @@ Serializers serializers = (_$serializers.toBuilder()
       ..add(const OneOfSerializer())
       ..add(const AnyOfSerializer())
       ..add(const DateSerializer())
-      ..add(Iso8601DateTimeSerializer()))
-    .build();
+      ..add(Iso8601DateTimeSerializer())
+    ).build();
 
 Serializers standardSerializers =
     (serializers.toBuilder()..addPlugin(StandardJsonPlugin())).build();