diff --git a/CHANGELOG.md b/CHANGELOG.md
index 73fb78aa..31cd9593 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,6 +4,11 @@
 
 ## [Unreleased]
 
+### Fixed
+- Fixed Bluetooth firmware updates sometimes failing on macOS. ([support#1787])
+
+[[support#1787]]: https://github.com/pybricks/support/issues/1787
+
 ## [2.3.0-beta.1] - 2023-11-24
 
 ### Changed
diff --git a/src/firmware/sagas.test.ts b/src/firmware/sagas.test.ts
index b335a58d..303c61c5 100644
--- a/src/firmware/sagas.test.ts
+++ b/src/firmware/sagas.test.ts
@@ -1,5 +1,5 @@
 // SPDX-License-Identifier: MIT
-// Copyright (c) 2021-2022 The Pybricks Authors
+// Copyright (c) 2021-2024 The Pybricks Authors
 
 import {
     FirmwareMetadata,
@@ -200,12 +200,12 @@ describe('flashFirmware', () => {
                     break;
                 }
 
-                if (count % 10 === 0) {
+                if (count % 8 === 0) {
                     action = await saga.take();
                     expect(action).toEqual(checksumRequest(++id));
 
                     saga.put(didRequest(id));
-                    saga.put(checksumResponse(0));
+                    saga.put(checksumResponse(0xee));
                 }
             }
 
@@ -366,7 +366,7 @@ describe('flashFirmware', () => {
                     break;
                 }
 
-                if (count % 10 === 0) {
+                if (count % 8 === 0) {
                     action = await saga.take();
                     expect(action).toEqual(checksumRequest(++id));
 
@@ -1331,12 +1331,12 @@ describe('flashFirmware', () => {
                     break;
                 }
 
-                if (count % 10 === 0) {
+                if (count % 8 === 0) {
                     action = await saga.take();
                     expect(action).toEqual(checksumRequest(++id));
 
                     saga.put(didRequest(id));
-                    saga.put(checksumResponse(0));
+                    saga.put(checksumResponse(0xeb));
                 }
             }
 
@@ -1507,12 +1507,12 @@ describe('flashFirmware', () => {
                     break;
                 }
 
-                if (count % 10 === 0) {
+                if (count % 8 === 0) {
                     action = await saga.take();
                     expect(action).toEqual(checksumRequest(++id));
 
                     saga.put(didRequest(id));
-                    saga.put(checksumResponse(0));
+                    saga.put(checksumResponse(0xeb));
                 }
             }
 
@@ -1689,7 +1689,7 @@ describe('flashFirmware', () => {
                     break;
                 }
 
-                if (count % 10 === 0) {
+                if (count % 8 === 0) {
                     action = await saga.take();
                     expect(action).toEqual(checksumRequest(++id));
 
@@ -2254,12 +2254,12 @@ describe('flashFirmware', () => {
                 break;
             }
 
-            if (count % 10 === 0) {
+            if (count % 8 === 0) {
                 action = await saga.take();
                 expect(action).toEqual(checksumRequest(++id));
 
                 saga.put(didRequest(id));
-                saga.put(checksumResponse(0));
+                saga.put(checksumResponse(0xeb));
             }
         }
 
diff --git a/src/firmware/sagas.ts b/src/firmware/sagas.ts
index 539471c8..782976bf 100644
--- a/src/firmware/sagas.ts
+++ b/src/firmware/sagas.ts
@@ -1,5 +1,5 @@
 // SPDX-License-Identifier: MIT
-// Copyright (c) 2020-2022 The Pybricks Authors
+// Copyright (c) 2020-2024 The Pybricks Authors
 
 import {
     FirmwareReader,
@@ -529,11 +529,11 @@ function* handleFlashFirmware(action: ReturnType<typeof flashFirmware>): Generat
                 break;
             }
 
-            // Request checksum every 10 packets to prevent buffer overrun on
+            // Request checksum every 8 packets to prevent buffer overrun on
             // the hub because of sending too much data at once. The actual
             // number of packets that can be queued in the Bluetooth chip on
             // the hub is not known and could vary by device.
-            if (count % 10 === 0) {
+            if (count % 8 === 0) {
                 const checksumAction = yield* put(checksumRequest(nextMessageId()));
 
                 const { response } = yield* all({
@@ -543,7 +543,7 @@ function* handleFlashFirmware(action: ReturnType<typeof flashFirmware>): Generat
 
                 if (response.checksum !== runningChecksum) {
                     // istanbul ignore next
-                    if (process.env.NODE_ENV !== 'test') {
+                    if (process.env.NODE_ENV === 'test') {
                         console.error(
                             `checksum: got ${hex(response.checksum, 2)} expected ${hex(
                                 runningChecksum,