diff --git a/lib/src/dart_formatter.dart b/lib/src/dart_formatter.dart
index 05841fa..31ee9ec 100644
--- a/lib/src/dart_formatter.dart
+++ b/lib/src/dart_formatter.dart
@@ -90,7 +90,7 @@
     var featureSet = FeatureSet.fromEnableFlags2(
       sdkLanguageVersion: Version(2, 19, 0),
       flags: [
-	'unnamed-libraries',
+        'unnamed-libraries',
       ],
     );