diff --git a/lib/src/device_screen_type.dart b/lib/src/device_screen_type.dart
index 311321d..fec24fc 100644
--- a/lib/src/device_screen_type.dart
+++ b/lib/src/device_screen_type.dart
@@ -1,16 +1,16 @@
 enum DeviceScreenType {
+  watch,
+  @Deprecated('Use lowercase version')
+  Watch,
+  mobile,
   @Deprecated('Use lowercase version')
   Mobile,
+  tablet,
   @Deprecated('Use lowercase version')
   Tablet,
+  desktop,
   @Deprecated('Use lowercase version')
   Desktop,
-  @Deprecated('Use lowercase version')
-  Watch,
-  mobile,
-  tablet,
-  desktop,
-  watch
 }
 
 enum RefinedSize { small, normal, large, extraLarge }
diff --git a/test/device_screen_type_test.dart b/test/device_screen_type_test.dart
new file mode 100644
index 0000000..0e8ebda
--- /dev/null
+++ b/test/device_screen_type_test.dart
@@ -0,0 +1,20 @@
+import 'package:flutter_test/flutter_test.dart';
+import 'package:responsive_builder/responsive_builder.dart';
+
+main() {
+  group('DeviceScreenType', () {
+    test('index', () {
+      final list = [
+        DeviceScreenType.watch,
+        DeviceScreenType.mobile,
+        DeviceScreenType.tablet,
+        DeviceScreenType.desktop,
+      ];
+      for (var i = 1; i < list.length; i++) {
+        final pre = list[i - 1];
+        final cur = list[i];
+        expect(pre.index < cur.index, true);
+      }
+    });
+  });
+}