diff --git a/lib/widgets/theme.dart b/lib/widgets/theme.dart
index c155ffafe8..ecc5478ef5 100644
--- a/lib/widgets/theme.dart
+++ b/lib/widgets/theme.dart
@@ -7,35 +7,10 @@ import 'message_list.dart';
 import 'channel_colors.dart';
 import 'text.dart';
 
-/// In debug mode, controls whether the UI responds to
-/// [MediaQueryData.platformBrightness].
-///
-/// Outside of debug mode, this is always false and the setter has no effect.
-// TODO(#95) when dark theme is fully implemented, simplify away;
-//   the UI should always respond.
-bool get debugFollowPlatformBrightness {
-  bool result = false;
-  assert(() {
-    result = _debugFollowPlatformBrightness;
-    return true;
-  }());
-  return result;
-}
-bool _debugFollowPlatformBrightness = false;
-set debugFollowPlatformBrightness(bool value) {
-  assert(() {
-    _debugFollowPlatformBrightness = value;
-    return true;
-  }());
-}
-
-
 ThemeData zulipThemeData(BuildContext context) {
   final DesignVariables designVariables;
   final List<ThemeExtension> themeExtensions;
-  Brightness brightness = debugFollowPlatformBrightness
-    ? MediaQuery.of(context).platformBrightness
-    : Brightness.light;
+  Brightness brightness = MediaQuery.platformBrightnessOf(context);
   switch (brightness) {
     case Brightness.light: {
       designVariables = DesignVariables.light();
diff --git a/test/widgets/emoji_reaction_test.dart b/test/widgets/emoji_reaction_test.dart
index fa96d1426e..a11d29c4ac 100644
--- a/test/widgets/emoji_reaction_test.dart
+++ b/test/widgets/emoji_reaction_test.dart
@@ -11,7 +11,6 @@ import 'package:zulip/api/model/events.dart';
 import 'package:zulip/api/model/model.dart';
 import 'package:zulip/model/store.dart';
 import 'package:zulip/widgets/emoji_reaction.dart';
-import 'package:zulip/widgets/theme.dart';
 
 import '../example_data.dart' as eg;
 import '../flutter_checks.dart';
@@ -221,9 +220,6 @@ void main() {
     await prepare();
     await store.addUsers([eg.selfUser, eg.otherUser]);
 
-    assert(!debugFollowPlatformBrightness); // to be removed with #95
-    debugFollowPlatformBrightness = true;
-    addTearDown(() { debugFollowPlatformBrightness = false; });
     tester.platformDispatcher.platformBrightnessTestValue = Brightness.light;
     addTearDown(tester.platformDispatcher.clearPlatformBrightnessTestValue);
 
diff --git a/test/widgets/message_list_test.dart b/test/widgets/message_list_test.dart
index 071823bf65..bc55b3b427 100644
--- a/test/widgets/message_list_test.dart
+++ b/test/widgets/message_list_test.dart
@@ -21,7 +21,6 @@ import 'package:zulip/widgets/icons.dart';
 import 'package:zulip/widgets/message_list.dart';
 import 'package:zulip/widgets/store.dart';
 import 'package:zulip/widgets/channel_colors.dart';
-import 'package:zulip/widgets/theme.dart';
 
 import '../api/fake_api.dart';
 import '../example_data.dart' as eg;
@@ -152,10 +151,6 @@ void main() {
   });
 
   testWidgets('smoke test for light/dark/lerped', (tester) async {
-    assert(!debugFollowPlatformBrightness); // to be removed with #95
-    debugFollowPlatformBrightness = true;
-    addTearDown(() { debugFollowPlatformBrightness = false; });
-
     tester.platformDispatcher.platformBrightnessTestValue = Brightness.light;
     addTearDown(tester.platformDispatcher.clearPlatformBrightnessTestValue);
 
diff --git a/test/widgets/theme_test.dart b/test/widgets/theme_test.dart
index eae672dddc..debe99419f 100644
--- a/test/widgets/theme_test.dart
+++ b/test/widgets/theme_test.dart
@@ -106,9 +106,6 @@ void main() {
 
       final subscription = eg.subscription(eg.stream(), color: baseColor);
 
-      assert(!debugFollowPlatformBrightness); // to be removed with #95
-      debugFollowPlatformBrightness = true;
-      addTearDown(() { debugFollowPlatformBrightness = false; });
       tester.platformDispatcher.platformBrightnessTestValue = Brightness.light;
       addTearDown(tester.platformDispatcher.clearPlatformBrightnessTestValue);