diff --git a/lib/src/etc/controllers/config_file.dart b/lib/src/etc/controllers/config_file.dart
index d586919..a7ec405 100644
--- a/lib/src/etc/controllers/config_file.dart
+++ b/lib/src/etc/controllers/config_file.dart
@@ -126,7 +126,7 @@ abstract class ConfigFile {
       sourceFile: sourceLocalizationFilePath,
       outputDir: outputDir,
       langs: targetLangsList,
-      languageLocalizationMaxDelay: languageLocalizationMaxDelay ?? 450,
+      languageLocalizationMaxDelay: languageLocalizationMaxDelay,
     ).toMap();
   }
 
diff --git a/lib/src/etc/controllers/json.dart b/lib/src/etc/controllers/json.dart
index 344e4b8..259a65b 100644
--- a/lib/src/etc/controllers/json.dart
+++ b/lib/src/etc/controllers/json.dart
@@ -2,6 +2,7 @@ import 'dart:convert';
 import 'dart:io';
 
 import 'package:langsync/src/etc/controllers/config_file.dart';
+import 'package:langsync/src/etc/extensions.dart';
 
 class JsonController extends ConfigFile {
   @override
@@ -19,7 +20,7 @@ class JsonController extends ConfigFile {
   @override
   Future<void> writeNewConfig(Map<String, dynamic> config) {
     return super.writeToConfigFile(
-      jsonEncode({'langsync': config}),
+      {'langsync': config}.toPrettyJson(),
     );
   }
 }
diff --git a/lib/src/etc/controllers/yaml.dart b/lib/src/etc/controllers/yaml.dart
index 1d1d40d..8c6d6d5 100644
--- a/lib/src/etc/controllers/yaml.dart
+++ b/lib/src/etc/controllers/yaml.dart
@@ -16,7 +16,14 @@ class YamlController extends ConfigFile {
     );
   }
 
-  Future<void> iterateAndWriteToConfigFile(
+  @override
+  Future<void> writeNewConfig(Map<String, dynamic> config) async {
+    await super.writeToConfigFile('langsync:\n');
+
+    await _iterateAndWriteToConfigFile(config);
+  }
+
+  Future<void> _iterateAndWriteToConfigFile(
     Map<dynamic, dynamic> config,
   ) async {
     super.iterateOverConfig(
@@ -34,11 +41,4 @@ class YamlController extends ConfigFile {
       },
     );
   }
-
-  @override
-  Future<void> writeNewConfig(Map<String, dynamic> config) async {
-    await super.writeToConfigFile('langsync:\n');
-
-    await iterateAndWriteToConfigFile(config);
-  }
 }
diff --git a/lib/src/etc/models/config.dart b/lib/src/etc/models/config.dart
index c5df905..8b9659f 100644
--- a/lib/src/etc/models/config.dart
+++ b/lib/src/etc/models/config.dart
@@ -6,7 +6,7 @@ class LangSyncConfig extends Equatable {
     required this.sourceFile,
     required this.outputDir,
     required this.langs,
-    required this.languageLocalizationMaxDelay,
+    this.languageLocalizationMaxDelay,
   });
 
   factory LangSyncConfig.fromMap(Map<dynamic, dynamic> map) {
@@ -21,14 +21,14 @@ class LangSyncConfig extends Equatable {
       outputDir: langsyncMapField['output'] as String,
       langs: target,
       languageLocalizationMaxDelay:
-          langsyncMapField['languageLocalizationMaxDelay'] as int,
+          (langsyncMapField['languageLocalizationMaxDelay'] as int?) ?? 450,
     );
   }
 
   final String sourceFile;
   final String outputDir;
   final Iterable<String> langs;
-  final int languageLocalizationMaxDelay;
+  final int? languageLocalizationMaxDelay;
 
   List<String> get langsJsonFiles => langs.map((e) => '$e.json').toList();
 
@@ -45,7 +45,7 @@ class LangSyncConfig extends Equatable {
       'source': sourceFile,
       'output': outputDir,
       'target': langs.toList(),
-      'languageLocalizationMaxDelay': languageLocalizationMaxDelay,
+      'languageLocalizationMaxDelay': languageLocalizationMaxDelay ?? 450,
     };
   }
 }