diff --git a/AUTHORS b/AUTHORS
index f7a1150b0f..591e37043d 100644
--- a/AUTHORS
+++ b/AUTHORS
@@ -81,3 +81,4 @@ Marian Triebe <m.triebe@live.de>
 Alexis Rouillard <contact@arouillard.fr>
 Mirko Mucaria <skogsfrae@gmail.com>
 Karol Czeryna <karol.czeryna@gmail.com>
+Callum Moffat <callum@moffatman.com>
diff --git a/packages/flutter/lib/src/gestures/converter.dart b/packages/flutter/lib/src/gestures/converter.dart
index 504dae2f84..5eb673d714 100644
--- a/packages/flutter/lib/src/gestures/converter.dart
+++ b/packages/flutter/lib/src/gestures/converter.dart
@@ -19,7 +19,7 @@ int _synthesiseDownButtons(int buttons, PointerDeviceKind kind) {
     case PointerDeviceKind.touch:
     case PointerDeviceKind.stylus:
     case PointerDeviceKind.invertedStylus:
-      return buttons | kPrimaryButton;
+      return buttons == 0 ? kPrimaryButton : buttons;
     case PointerDeviceKind.unknown:
       // We have no information about the device but we know we never want
       // buttons to be 0 when the pointer is down.
diff --git a/packages/flutter/test/gestures/gesture_binding_test.dart b/packages/flutter/test/gestures/gesture_binding_test.dart
index c8143834a1..fb2ea9a3de 100644
--- a/packages/flutter/test/gestures/gesture_binding_test.dart
+++ b/packages/flutter/test/gestures/gesture_binding_test.dart
@@ -175,7 +175,7 @@ void main() {
     expect(events[1], isA<PointerScrollEvent>());
   });
 
-  test('Should synthesize kPrimaryButton for touch', () {
+  test('Should synthesize kPrimaryButton for touch when no button is set', () {
     final Offset location = const Offset(10.0, 10.0) * ui.window.devicePixelRatio;
     const PointerDeviceKind kind = PointerDeviceKind.touch;
     final ui.PointerDataPacket packet = ui.PointerDataPacket(
@@ -203,7 +203,35 @@ void main() {
     expect(events[4].buttons, equals(0));
   });
 
-  test('Should synthesize kPrimaryButton for stylus', () {
+  test('Should not synthesize kPrimaryButton for touch when a button is set', () {
+    final Offset location = const Offset(10.0, 10.0) * ui.window.devicePixelRatio;
+    const PointerDeviceKind kind = PointerDeviceKind.touch;
+    final ui.PointerDataPacket packet = ui.PointerDataPacket(
+      data: <ui.PointerData>[
+        ui.PointerData(change: ui.PointerChange.add, kind: kind, physicalX: location.dx, physicalY: location.dy),
+        ui.PointerData(change: ui.PointerChange.hover, kind: kind, physicalX: location.dx, physicalY: location.dy),
+        ui.PointerData(change: ui.PointerChange.down, buttons: kSecondaryButton, kind: kind, physicalX: location.dx, physicalY: location.dy),
+        ui.PointerData(change: ui.PointerChange.move, buttons: kSecondaryButton, kind: kind, physicalX: location.dx, physicalY: location.dy),
+        ui.PointerData(change: ui.PointerChange.up, kind: kind, physicalX: location.dx, physicalY: location.dy),
+      ],
+    );
+
+    final List<PointerEvent> events = PointerEventConverter.expand(packet.data, ui.window.devicePixelRatio).toList();
+
+    expect(events.length, 5);
+    expect(events[0], isA<PointerAddedEvent>());
+    expect(events[0].buttons, equals(0));
+    expect(events[1], isA<PointerHoverEvent>());
+    expect(events[1].buttons, equals(0));
+    expect(events[2], isA<PointerDownEvent>());
+    expect(events[2].buttons, equals(kSecondaryButton));
+    expect(events[3], isA<PointerMoveEvent>());
+    expect(events[3].buttons, equals(kSecondaryButton));
+    expect(events[4], isA<PointerUpEvent>());
+    expect(events[4].buttons, equals(0));
+  });
+
+  test('Should synthesize kPrimaryButton for stylus when no button is set', () {
     final Offset location = const Offset(10.0, 10.0) * ui.window.devicePixelRatio;
     for (final PointerDeviceKind kind in <PointerDeviceKind>[
       PointerDeviceKind.stylus,
@@ -230,13 +258,13 @@ void main() {
       expect(events[2], isA<PointerDownEvent>());
       expect(events[2].buttons, equals(kPrimaryButton));
       expect(events[3], isA<PointerMoveEvent>());
-      expect(events[3].buttons, equals(kPrimaryButton | kSecondaryStylusButton));
+      expect(events[3].buttons, equals(kSecondaryStylusButton));
       expect(events[4], isA<PointerUpEvent>());
       expect(events[4].buttons, equals(0));
     }
   });
 
-  test('Should synthesize kPrimaryButton for unknown devices', () {
+  test('Should synthesize kPrimaryButton for unknown devices when no button is set', () {
     final Offset location = const Offset(10.0, 10.0) * ui.window.devicePixelRatio;
     const PointerDeviceKind kind = PointerDeviceKind.unknown;
     final ui.PointerDataPacket packet = ui.PointerDataPacket(
@@ -244,7 +272,7 @@ void main() {
         ui.PointerData(change: ui.PointerChange.add, kind: kind, physicalX: location.dx, physicalY: location.dy),
         ui.PointerData(change: ui.PointerChange.hover, kind: kind, physicalX: location.dx, physicalY: location.dy),
         ui.PointerData(change: ui.PointerChange.down, kind: kind, physicalX: location.dx, physicalY: location.dy),
-        ui.PointerData(change: ui.PointerChange.move, kind: kind, physicalX: location.dx, physicalY: location.dy),
+        ui.PointerData(change: ui.PointerChange.move, buttons: kSecondaryButton, kind: kind, physicalX: location.dx, physicalY: location.dy),
         ui.PointerData(change: ui.PointerChange.up, kind: kind, physicalX: location.dx, physicalY: location.dy),
       ],
     );
@@ -259,7 +287,7 @@ void main() {
     expect(events[2], isA<PointerDownEvent>());
     expect(events[2].buttons, equals(kPrimaryButton));
     expect(events[3], isA<PointerMoveEvent>());
-    expect(events[3].buttons, equals(kPrimaryButton));
+    expect(events[3].buttons, equals(kSecondaryButton));
     expect(events[4], isA<PointerUpEvent>());
     expect(events[4].buttons, equals(0));
   });