diff --git a/design_system/lib/src/confirm.dart b/design_system/lib/src/confirm.dart
index 39d5f14..7ea247c 100644
--- a/design_system/lib/src/confirm.dart
+++ b/design_system/lib/src/confirm.dart
@@ -1,8 +1,8 @@
 /// Confirmation for destructive actions.
 library;
 
-import 'package:flutter/material.dart';
 import 'package:flutter/services.dart';
+import 'package:material_ui/material_ui.dart';
 
 /// Asks the user to confirm a destructive action, returning true if they do.
 ///
diff --git a/design_system/lib/src/empty_state.dart b/design_system/lib/src/empty_state.dart
index 2847532..5e7a098 100644
--- a/design_system/lib/src/empty_state.dart
+++ b/design_system/lib/src/empty_state.dart
@@ -2,7 +2,7 @@
 library;
 
 import 'package:design_system/src/tokens.dart';
-import 'package:flutter/material.dart';
+import 'package:material_ui/material_ui.dart';
 
 /// A centred icon, headline and explanation for an empty list.
 ///
diff --git a/design_system/lib/src/feedback.dart b/design_system/lib/src/feedback.dart
index d1c72a1..93cc290 100644
--- a/design_system/lib/src/feedback.dart
+++ b/design_system/lib/src/feedback.dart
@@ -8,7 +8,7 @@ library;
 
 import 'package:design_system/src/status_colors.dart';
 import 'package:design_system/src/tokens.dart';
-import 'package:flutter/material.dart';
+import 'package:material_ui/material_ui.dart';
 
 /// How long a neutral confirmation stays up.
 const Duration _toastDuration = Duration(seconds: 3);
diff --git a/design_system/lib/src/fit_grid.dart b/design_system/lib/src/fit_grid.dart
index c28e9ee..7ec2d85 100644
--- a/design_system/lib/src/fit_grid.dart
+++ b/design_system/lib/src/fit_grid.dart
@@ -1,7 +1,7 @@
 import 'dart:math' as math;
 
 import 'package:design_system/src/tokens.dart';
-import 'package:flutter/material.dart';
+import 'package:material_ui/material_ui.dart';
 
 /// A grid of square cells that always fits its box, so it never scrolls
 /// vertically.
diff --git a/design_system/lib/src/section_header.dart b/design_system/lib/src/section_header.dart
index 1ceec61..857f21d 100644
--- a/design_system/lib/src/section_header.dart
+++ b/design_system/lib/src/section_header.dart
@@ -2,7 +2,7 @@
 library;
 
 import 'package:design_system/src/tokens.dart';
-import 'package:flutter/material.dart';
+import 'package:material_ui/material_ui.dart';
 
 /// A section title, optionally with a trailing action.
 ///
@@ -13,12 +13,7 @@ import 'package:flutter/material.dart';
 /// caller can adopt it without a visual change.
 class SectionHeader extends StatelessWidget {
   /// Creates a section header.
-  const SectionHeader(
-    this.title, {
-    this.action,
-    this.padding,
-    super.key,
-  });
+  const SectionHeader(this.title, {this.action, this.padding, super.key});
 
   /// The section's title.
   final String title;
diff --git a/design_system/lib/src/status_colors.dart b/design_system/lib/src/status_colors.dart
index 339270d..4341220 100644
--- a/design_system/lib/src/status_colors.dart
+++ b/design_system/lib/src/status_colors.dart
@@ -8,7 +8,7 @@
 library;
 
 import 'package:design_system/src/tokens.dart';
-import 'package:flutter/material.dart';
+import 'package:material_ui/material_ui.dart';
 
 /// The four status colors, plus the text color to draw on top of them.
 @immutable
diff --git a/design_system/lib/src/theme.dart b/design_system/lib/src/theme.dart
index c75eb1d..0d2bffc 100644
--- a/design_system/lib/src/theme.dart
+++ b/design_system/lib/src/theme.dart
@@ -7,7 +7,7 @@ library;
 
 import 'package:design_system/src/status_colors.dart';
 import 'package:design_system/src/tokens.dart';
-import 'package:flutter/material.dart';
+import 'package:material_ui/material_ui.dart';
 
 /// Builds the shared light [ThemeData].
 ThemeData buildLightTheme() {
diff --git a/design_system/pubspec.yaml b/design_system/pubspec.yaml
index 74d788f..35c69d2 100644
--- a/design_system/pubspec.yaml
+++ b/design_system/pubspec.yaml
@@ -5,7 +5,7 @@ description: >-
   helpers that were each reimplemented in three or more repos. Owns the tokens
   -- consumers import them rather than transcribing the token table by hand.
 publish_to: 'none'
-version: 0.3.1
+version: 0.4.0
 
 environment:
   sdk: ^3.12.2
@@ -13,6 +13,7 @@ environment:
 dependencies:
   flutter:
     sdk: flutter
+  material_ui: 1.11.0
 
 dev_dependencies:
   flutter_test:
diff --git a/design_system/test/confirm_test.dart b/design_system/test/confirm_test.dart
index 4d1c915..05abf75 100644
--- a/design_system/test/confirm_test.dart
+++ b/design_system/test/confirm_test.dart
@@ -1,5 +1,5 @@
 import 'package:design_system/design_system.dart';
-import 'package:flutter/material.dart';
+import 'package:material_ui/material_ui.dart';
 import 'package:flutter/services.dart';
 import 'package:flutter_test/flutter_test.dart';
 
diff --git a/design_system/test/empty_state_test.dart b/design_system/test/empty_state_test.dart
index 08c90a9..fbfd4ad 100644
--- a/design_system/test/empty_state_test.dart
+++ b/design_system/test/empty_state_test.dart
@@ -1,5 +1,5 @@
 import 'package:design_system/design_system.dart';
-import 'package:flutter/material.dart';
+import 'package:material_ui/material_ui.dart';
 import 'package:flutter_test/flutter_test.dart';
 
 /// Built at runtime rather than inlined as a literal, so the `EmptyState`
@@ -44,9 +44,7 @@ void main() {
     await _pumpEmptyState(tester);
     final scheme = buildDarkTheme().colorScheme;
 
-    final message = tester.widget<Text>(
-      find.text(_message(0)),
-    );
+    final message = tester.widget<Text>(find.text(_message(0)));
     expect(message.style?.color, scheme.onSurfaceVariant);
     expect(message.textAlign, TextAlign.center);
 
diff --git a/design_system/test/feedback_test.dart b/design_system/test/feedback_test.dart
index 297d775..2ffa538 100644
--- a/design_system/test/feedback_test.dart
+++ b/design_system/test/feedback_test.dart
@@ -1,5 +1,5 @@
 import 'package:design_system/design_system.dart';
-import 'package:flutter/material.dart';
+import 'package:material_ui/material_ui.dart';
 import 'package:flutter_test/flutter_test.dart';
 
 /// Pumps a screen whose button calls [onPressed] with a context that has a
diff --git a/design_system/test/fit_grid_test.dart b/design_system/test/fit_grid_test.dart
index 931c220..2ece775 100644
--- a/design_system/test/fit_grid_test.dart
+++ b/design_system/test/fit_grid_test.dart
@@ -1,5 +1,5 @@
 import 'package:design_system/design_system.dart';
-import 'package:flutter/material.dart';
+import 'package:material_ui/material_ui.dart';
 import 'package:flutter_test/flutter_test.dart';
 
 final _dot = find.byWidgetPredicate(
diff --git a/design_system/test/section_header_test.dart b/design_system/test/section_header_test.dart
index 762e6a1..9a7a466 100644
--- a/design_system/test/section_header_test.dart
+++ b/design_system/test/section_header_test.dart
@@ -1,5 +1,5 @@
 import 'package:design_system/design_system.dart';
-import 'package:flutter/material.dart';
+import 'package:material_ui/material_ui.dart';
 import 'package:flutter_test/flutter_test.dart';
 
 Future<void> _pumpHeader(
diff --git a/design_system/test/status_colors_test.dart b/design_system/test/status_colors_test.dart
index bb007a5..8c2bf9a 100644
--- a/design_system/test/status_colors_test.dart
+++ b/design_system/test/status_colors_test.dart
@@ -1,5 +1,5 @@
 import 'package:design_system/design_system.dart';
-import 'package:flutter/material.dart';
+import 'package:material_ui/material_ui.dart';
 import 'package:flutter_test/flutter_test.dart';
 
 void main() {
diff --git a/design_system/test/theme_test.dart b/design_system/test/theme_test.dart
index b31b1af..805974f 100644
--- a/design_system/test/theme_test.dart
+++ b/design_system/test/theme_test.dart
@@ -1,5 +1,5 @@
 import 'package:design_system/design_system.dart';
-import 'package:flutter/material.dart';
+import 'package:material_ui/material_ui.dart';
 import 'package:flutter_test/flutter_test.dart';
 
 void main() {
@@ -100,10 +100,7 @@ void main() {
         final focused = input.focusedBorder! as OutlineInputBorder;
         expect(focused.borderSide.color, AppPalette.accent);
         expect(focused.borderSide.width, 2.0);
-        expect(
-          focused.borderRadius,
-          BorderRadius.circular(AppRadius.sm),
-        );
+        expect(focused.borderRadius, BorderRadius.circular(AppRadius.sm));
 
         for (final border in [input.border!, input.enabledBorder!]) {
           expect(
diff --git a/design_system/test/tokens_test.dart b/design_system/test/tokens_test.dart
index f0e520e..3df61e5 100644
--- a/design_system/test/tokens_test.dart
+++ b/design_system/test/tokens_test.dart
@@ -1,5 +1,5 @@
 import 'package:design_system/design_system.dart';
-import 'package:flutter/material.dart';
+import 'package:material_ui/material_ui.dart';
 import 'package:flutter_test/flutter_test.dart';
 
 void main() {