diff --git a/packages/flutter/lib/src/cupertino/activity_indicator.dart b/packages/flutter/lib/src/cupertino/activity_indicator.dart
index d4c1aafe14d..b624f902199 100644
--- a/packages/flutter/lib/src/cupertino/activity_indicator.dart
+++ b/packages/flutter/lib/src/cupertino/activity_indicator.dart
@@ -49,6 +49,7 @@ class _CupertinoActivityIndicatorState extends State<CupertinoActivityIndicator>
 
   @override
   void didUpdateWidget(CupertinoActivityIndicator oldWidget) {
+    super.didUpdateWidget(oldWidget);
     if (widget.animating != oldWidget.animating) {
       if (widget.animating)
         _controller.repeat();
diff --git a/packages/flutter/lib/src/material/bottom_navigation_bar.dart b/packages/flutter/lib/src/material/bottom_navigation_bar.dart
index 285c88f7890..d868495b1e1 100644
--- a/packages/flutter/lib/src/material/bottom_navigation_bar.dart
+++ b/packages/flutter/lib/src/material/bottom_navigation_bar.dart
@@ -291,6 +291,7 @@ class _BottomNavigationBarState extends State<BottomNavigationBar> with TickerPr
 
   @override
   void didUpdateWidget(BottomNavigationBar oldWidget) {
+    super.didUpdateWidget(oldWidget);
     if (widget.currentIndex != oldWidget.currentIndex) {
       if (widget.type == BottomNavigationBarType.shifting)
         _pushCircle(widget.currentIndex);
diff --git a/packages/flutter/lib/src/material/date_picker.dart b/packages/flutter/lib/src/material/date_picker.dart
index 2d8762086de..ab562739d54 100644
--- a/packages/flutter/lib/src/material/date_picker.dart
+++ b/packages/flutter/lib/src/material/date_picker.dart
@@ -372,6 +372,7 @@ class _MonthPickerState extends State<MonthPicker> {
 
   @override
   void didUpdateWidget(MonthPicker oldWidget) {
+    super.didUpdateWidget(oldWidget);
     if (widget.selectedDate != oldWidget.selectedDate) {
       _dayPickerController = new PageController(initialPage: _monthDelta(widget.firstDate, widget.selectedDate));
       _currentDisplayedMonthDate =
diff --git a/packages/flutter/lib/src/material/dropdown.dart b/packages/flutter/lib/src/material/dropdown.dart
index 0eaadc65b1d..385958aea52 100644
--- a/packages/flutter/lib/src/material/dropdown.dart
+++ b/packages/flutter/lib/src/material/dropdown.dart
@@ -480,6 +480,7 @@ class _DropdownButtonState<T> extends State<DropdownButton<T>> {
 
  @override
   void didUpdateWidget(DropdownButton<T> oldWidget) {
+    super.didUpdateWidget(oldWidget);
     _updateSelectedIndex();
   }
 
diff --git a/packages/flutter/lib/src/material/expand_icon.dart b/packages/flutter/lib/src/material/expand_icon.dart
index 0c4140ab964..ade426e36b8 100644
--- a/packages/flutter/lib/src/material/expand_icon.dart
+++ b/packages/flutter/lib/src/material/expand_icon.dart
@@ -84,6 +84,7 @@ class _ExpandIconState extends State<ExpandIcon> with SingleTickerProviderStateM
 
   @override
   void didUpdateWidget(ExpandIcon oldWidget) {
+    super.didUpdateWidget(oldWidget);
     if (widget.isExpanded != oldWidget.isExpanded) {
       if (widget.isExpanded) {
         _controller.forward();
diff --git a/packages/flutter/lib/src/material/scaffold.dart b/packages/flutter/lib/src/material/scaffold.dart
index 8157c0427de..11aa6e9053d 100644
--- a/packages/flutter/lib/src/material/scaffold.dart
+++ b/packages/flutter/lib/src/material/scaffold.dart
@@ -196,6 +196,7 @@ class _FloatingActionButtonTransitionState extends State<_FloatingActionButtonTr
 
   @override
   void didUpdateWidget(_FloatingActionButtonTransition oldWidget) {
+    super.didUpdateWidget(oldWidget);
     final bool oldChildIsNull = oldWidget.child == null;
     final bool newChildIsNull = widget.child == null;
     if (oldChildIsNull == newChildIsNull && oldWidget.child?.key == widget.child?.key)
diff --git a/packages/flutter/lib/src/material/text_field.dart b/packages/flutter/lib/src/material/text_field.dart
index a42966e2c0a..3641bb335d0 100644
--- a/packages/flutter/lib/src/material/text_field.dart
+++ b/packages/flutter/lib/src/material/text_field.dart
@@ -183,6 +183,7 @@ class _TextFieldState extends State<TextField> {
 
   @override
   void didUpdateWidget(TextField oldWidget) {
+    super.didUpdateWidget(oldWidget);
     if (widget.controller == null && oldWidget.controller != null)
       _controller == new TextEditingController.fromValue(oldWidget.controller.value);
     else if (widget.controller != null && oldWidget.controller == null)
diff --git a/packages/flutter/lib/src/material/time_picker.dart b/packages/flutter/lib/src/material/time_picker.dart
index 17b4c632802..0367f5c4275 100644
--- a/packages/flutter/lib/src/material/time_picker.dart
+++ b/packages/flutter/lib/src/material/time_picker.dart
@@ -479,6 +479,7 @@ class _DialState extends State<_Dial> with SingleTickerProviderStateMixin {
 
   @override
   void didUpdateWidget(_Dial oldWidget) {
+    super.didUpdateWidget(oldWidget);
     if (widget.mode != oldWidget.mode && !_dragging)
       _animateTo(_getThetaForTime(widget.selectedTime));
   }
diff --git a/packages/flutter/lib/src/widgets/async.dart b/packages/flutter/lib/src/widgets/async.dart
index 9119fd20559..8bc039c7fdc 100644
--- a/packages/flutter/lib/src/widgets/async.dart
+++ b/packages/flutter/lib/src/widgets/async.dart
@@ -107,6 +107,7 @@ class _StreamBuilderBaseState<T, S> extends State<StreamBuilderBase<T, S>> {
 
   @override
   void didUpdateWidget(StreamBuilderBase<T, S> oldWidget) {
+    super.didUpdateWidget(oldWidget);
     if (oldWidget.stream != widget.stream) {
       if (_subscription != null) {
         _unsubscribe();
@@ -419,6 +420,7 @@ class _FutureBuilderState<T> extends State<FutureBuilder<T>> {
 
   @override
   void didUpdateWidget(FutureBuilder<T> oldWidget) {
+    super.didUpdateWidget(oldWidget);
     if (oldWidget.future != widget.future) {
       if (_activeCallbackIdentity != null) {
         _unsubscribe();
diff --git a/packages/flutter/lib/src/widgets/editable_text.dart b/packages/flutter/lib/src/widgets/editable_text.dart
index 34b998e425a..d8800709b1d 100644
--- a/packages/flutter/lib/src/widgets/editable_text.dart
+++ b/packages/flutter/lib/src/widgets/editable_text.dart
@@ -236,6 +236,7 @@ class EditableTextState extends State<EditableText> implements TextInputClient {
 
   @override
   void didUpdateWidget(EditableText oldWidget) {
+    super.didUpdateWidget(oldWidget);
     if (widget.controller != oldWidget.controller) {
       oldWidget.controller.removeListener(_didChangeTextEditingValue);
       widget.controller.addListener(_didChangeTextEditingValue);
diff --git a/packages/flutter/lib/src/widgets/framework.dart b/packages/flutter/lib/src/widgets/framework.dart
index d26387394c1..e56cb97b8d1 100644
--- a/packages/flutter/lib/src/widgets/framework.dart
+++ b/packages/flutter/lib/src/widgets/framework.dart
@@ -831,7 +831,7 @@ abstract class State<T extends StatefulWidget> {
   ///
   /// If you override this, make sure your method starts with a call to
   /// super.didUpdateWidget(oldWidget).
-  // TODO(abarth): Add @mustCallSuper.
+  @mustCallSuper
   @protected
   void didUpdateWidget(covariant T oldWidget) { }
 
diff --git a/packages/flutter/lib/src/widgets/gesture_detector.dart b/packages/flutter/lib/src/widgets/gesture_detector.dart
index 5c2b5353fcc..03b60f8f276 100644
--- a/packages/flutter/lib/src/widgets/gesture_detector.dart
+++ b/packages/flutter/lib/src/widgets/gesture_detector.dart
@@ -368,6 +368,7 @@ class RawGestureDetectorState extends State<RawGestureDetector> {
 
   @override
   void didUpdateWidget(RawGestureDetector oldWidget) {
+    super.didUpdateWidget(oldWidget);
     _syncAll(widget.gestures);
   }
 
diff --git a/packages/flutter/lib/src/widgets/image.dart b/packages/flutter/lib/src/widgets/image.dart
index 9ab5a49ea11..38153bb8b7c 100644
--- a/packages/flutter/lib/src/widgets/image.dart
+++ b/packages/flutter/lib/src/widgets/image.dart
@@ -244,6 +244,7 @@ class _ImageState extends State<Image> {
 
   @override
   void didUpdateWidget(Image oldWidget) {
+    super.didUpdateWidget(oldWidget);
     if (widget.image != oldWidget.image)
       _resolveImage();
   }
diff --git a/packages/flutter/lib/src/widgets/implicit_animations.dart b/packages/flutter/lib/src/widgets/implicit_animations.dart
index 990cb015c90..785a795adc5 100644
--- a/packages/flutter/lib/src/widgets/implicit_animations.dart
+++ b/packages/flutter/lib/src/widgets/implicit_animations.dart
@@ -148,6 +148,7 @@ abstract class AnimatedWidgetBaseState<T extends ImplicitlyAnimatedWidget> exten
 
   @override
   void didUpdateWidget(T oldWidget) {
+    super.didUpdateWidget(oldWidget);
     if (widget.curve != oldWidget.curve)
       _updateCurve();
     _controller.duration = widget.duration;
@@ -229,11 +230,11 @@ abstract class AnimatedWidgetBaseState<T extends ImplicitlyAnimatedWidget> exten
 /// The [AnimatedContainer] will automatically animate between the old and
 /// new values of properties when they change using the provided curve and
 /// duration. Properties that are null are not animated.
-/// 
+///
 /// This class is useful for generating simple implicit transitions between
 /// different parameters to [Container] with its internal
 /// [AnimationController]. For more complex animations, you'll likely want to
-/// use a subclass of [Transition] such as the [DecoratedBoxTransition] or use 
+/// use a subclass of [Transition] such as the [DecoratedBoxTransition] or use
 /// your own [AnimationController].
 class AnimatedContainer extends ImplicitlyAnimatedWidget {
   /// Creates a container that animates its parameters implicitly.
diff --git a/packages/flutter/lib/src/widgets/navigator.dart b/packages/flutter/lib/src/widgets/navigator.dart
index 0e4615d4a4f..4f4cfea0c5c 100644
--- a/packages/flutter/lib/src/widgets/navigator.dart
+++ b/packages/flutter/lib/src/widgets/navigator.dart
@@ -716,6 +716,7 @@ class NavigatorState extends State<Navigator> with TickerProviderStateMixin {
 
   @override
   void didUpdateWidget(Navigator oldWidget) {
+    super.didUpdateWidget(oldWidget);
     if (oldWidget.observers != widget.observers) {
       for (NavigatorObserver observer in oldWidget.observers)
         observer._navigator = null;
diff --git a/packages/flutter/lib/src/widgets/overscroll_indicator.dart b/packages/flutter/lib/src/widgets/overscroll_indicator.dart
index 64aeafeb928..ab120409092 100644
--- a/packages/flutter/lib/src/widgets/overscroll_indicator.dart
+++ b/packages/flutter/lib/src/widgets/overscroll_indicator.dart
@@ -122,6 +122,7 @@ class _GlowingOverscrollIndicatorState extends State<GlowingOverscrollIndicator>
 
   @override
   void didUpdateWidget(GlowingOverscrollIndicator oldWidget) {
+    super.didUpdateWidget(oldWidget);
     if (oldWidget.color != widget.color || oldWidget.axis != widget.axis) {
       _leadingController.color = widget.color;
       _leadingController.axis = widget.axis;
diff --git a/packages/flutter/lib/src/widgets/raw_keyboard_listener.dart b/packages/flutter/lib/src/widgets/raw_keyboard_listener.dart
index b4f54d66275..8a0d7c3e620 100644
--- a/packages/flutter/lib/src/widgets/raw_keyboard_listener.dart
+++ b/packages/flutter/lib/src/widgets/raw_keyboard_listener.dart
@@ -60,6 +60,7 @@ class _RawKeyboardListenerState extends State<RawKeyboardListener> {
 
   @override
   void didUpdateWidget(RawKeyboardListener oldWidget) {
+    super.didUpdateWidget(oldWidget);
     if (widget.focusNode != oldWidget.focusNode) {
       oldWidget.focusNode.removeListener(_handleFocusChanged);
       widget.focusNode.addListener(_handleFocusChanged);
diff --git a/packages/flutter/lib/src/widgets/routes.dart b/packages/flutter/lib/src/widgets/routes.dart
index 01542991cdd..684056d3537 100644
--- a/packages/flutter/lib/src/widgets/routes.dart
+++ b/packages/flutter/lib/src/widgets/routes.dart
@@ -442,6 +442,7 @@ class _ModalScopeState extends State<_ModalScope> {
 
   @override
   void didUpdateWidget(_ModalScope oldWidget) {
+    super.didUpdateWidget(oldWidget);
     assert(widget.route == oldWidget.route);
   }
 
diff --git a/packages/flutter/lib/src/widgets/status_transitions.dart b/packages/flutter/lib/src/widgets/status_transitions.dart
index 1909d264373..6b6fc6c2e79 100644
--- a/packages/flutter/lib/src/widgets/status_transitions.dart
+++ b/packages/flutter/lib/src/widgets/status_transitions.dart
@@ -39,6 +39,7 @@ class _StatusTransitionState extends State<StatusTransitionWidget> {
 
   @override
   void didUpdateWidget(StatusTransitionWidget oldWidget) {
+    super.didUpdateWidget(oldWidget);
     if (widget.animation != oldWidget.animation) {
       oldWidget.animation.removeStatusListener(_animationStatusChanged);
       widget.animation.addStatusListener(_animationStatusChanged);
diff --git a/packages/flutter/lib/src/widgets/transitions.dart b/packages/flutter/lib/src/widgets/transitions.dart
index 65cac3cc832..34f33599f49 100644
--- a/packages/flutter/lib/src/widgets/transitions.dart
+++ b/packages/flutter/lib/src/widgets/transitions.dart
@@ -74,6 +74,7 @@ class _AnimatedState extends State<AnimatedWidget> {
 
   @override
   void didUpdateWidget(AnimatedWidget oldWidget) {
+    super.didUpdateWidget(oldWidget);
     if (widget.listenable != oldWidget.listenable) {
       oldWidget.listenable.removeListener(_handleChange);
       widget.listenable.addListener(_handleChange);
@@ -391,20 +392,20 @@ class RelativePositionedTransition extends AnimatedWidget {
 
 /// Animated version of a [DecoratedBox] that animates the different properties
 /// of its [Decoration].
-/// 
+///
 /// See also:
 ///
 /// * [DecoratedBox], which also draws a [Decoration] but is not animated.
-/// * [AnimatedContainer], a more full-featured container that also animates on 
+/// * [AnimatedContainer], a more full-featured container that also animates on
 ///   decoration using an internal animation.
 class DecoratedBoxTransition extends AnimatedWidget {
   /// Creates an animated [DecorationBox] whose [Decoration] animation updates
-  /// the widget. 
-  /// 
-  /// The [decoration] and [position] cannot be null. 
-  /// 
+  /// the widget.
+  ///
+  /// The [decoration] and [position] cannot be null.
+  ///
   /// See also:
-  /// 
+  ///
   /// * [new DecoratedBox].
   DecoratedBoxTransition({
     Key key,
diff --git a/packages/flutter/lib/src/widgets/will_pop_scope.dart b/packages/flutter/lib/src/widgets/will_pop_scope.dart
index 8acd574ecf4..7bb4620db8f 100644
--- a/packages/flutter/lib/src/widgets/will_pop_scope.dart
+++ b/packages/flutter/lib/src/widgets/will_pop_scope.dart
@@ -55,6 +55,7 @@ class _WillPopScopeState extends State<WillPopScope> {
 
   @override
   void didUpdateWidget(WillPopScope oldWidget) {
+    super.didUpdateWidget(oldWidget);
     assert(_route == ModalRoute.of(context));
     if (widget.onWillPop != oldWidget.onWillPop && _route != null) {
       if (oldWidget.onWillPop != null)
diff --git a/packages/flutter/test/widgets/build_scope_test.dart b/packages/flutter/test/widgets/build_scope_test.dart
index 00f66d3788f..deb862c7a3d 100644
--- a/packages/flutter/test/widgets/build_scope_test.dart
+++ b/packages/flutter/test/widgets/build_scope_test.dart
@@ -23,6 +23,7 @@ class ProbeWidgetState extends State<ProbeWidget> {
 
   @override
   void didUpdateWidget(ProbeWidget oldWidget) {
+    super.didUpdateWidget(oldWidget);
     setState(() {});
   }
 
diff --git a/packages/flutter/test/widgets/independent_widget_layout_test.dart b/packages/flutter/test/widgets/independent_widget_layout_test.dart
index 1e1b64c46b8..9e31a30059b 100644
--- a/packages/flutter/test/widgets/independent_widget_layout_test.dart
+++ b/packages/flutter/test/widgets/independent_widget_layout_test.dart
@@ -78,6 +78,7 @@ class TriggerableState extends State<TriggerableWidget> {
 
   @override
   void didUpdateWidget(TriggerableWidget oldWidget) {
+    super.didUpdateWidget(oldWidget);
     widget.trigger.callback = fire;
   }
 
diff --git a/packages/flutter/test/widgets/syncing_test.dart b/packages/flutter/test/widgets/syncing_test.dart
index dffc47b390f..05293878ade 100644
--- a/packages/flutter/test/widgets/syncing_test.dart
+++ b/packages/flutter/test/widgets/syncing_test.dart
@@ -30,6 +30,7 @@ class TestWidgetState extends State<TestWidget> {
 
   @override
   void didUpdateWidget(TestWidget oldWidget) {
+    super.didUpdateWidget(oldWidget);
     syncedState = widget.syncedState;
     // we explicitly do NOT sync the persistentState from the new instance
     // because we're using that to track whether we got recreated