diff --git a/CHANGELOG.md b/CHANGELOG.md
index 33cf072e..81e9a1df 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,6 +4,9 @@
 
 ## [Unreleased]
 
+### Changed
+- Better error message when download and run fails due to disconnected hub.
+
 ### Fixed
 - Fixed run button active while hub is disconnecting ([support#1021]).
 
diff --git a/src/ble/alerts/Disconnected.test.tsx b/src/ble/alerts/Disconnected.test.tsx
new file mode 100644
index 00000000..cc872083
--- /dev/null
+++ b/src/ble/alerts/Disconnected.test.tsx
@@ -0,0 +1,19 @@
+// SPDX-License-Identifier: MIT
+// Copyright (c) 2022-2023 The Pybricks Authors
+
+import { Toast } from '@blueprintjs/core';
+import { act } from '@testing-library/react';
+import React from 'react';
+import { testRender } from '../../../test';
+import { disconnected } from './Disconnected';
+
+it('should dismiss when close is clicked', async () => {
+    const callback = jest.fn();
+    const toast = disconnected(callback, undefined as never);
+
+    const [user, message] = testRender(<Toast {...toast} />);
+
+    await act(() => user.click(message.getByRole('button', { name: /close/i })));
+
+    expect(callback).toHaveBeenCalledWith('dismiss');
+});
diff --git a/src/ble/alerts/Disconnected.tsx b/src/ble/alerts/Disconnected.tsx
new file mode 100644
index 00000000..93b43a2c
--- /dev/null
+++ b/src/ble/alerts/Disconnected.tsx
@@ -0,0 +1,19 @@
+// SPDX-License-Identifier: MIT
+// Copyright (c) 2022-2023 The Pybricks Authors
+
+import { Intent } from '@blueprintjs/core';
+import React from 'react';
+import type { CreateToast } from '../../toasterTypes';
+import { useI18n } from './i18n';
+
+const Disconnected: React.VoidFunctionComponent = () => {
+    const i18n = useI18n();
+    return <p>{i18n.translate('disconnected.message')}</p>;
+};
+
+export const disconnected: CreateToast = (onAction) => ({
+    message: <Disconnected />,
+    icon: 'error',
+    intent: Intent.DANGER,
+    onDismiss: () => onAction('dismiss'),
+});
diff --git a/src/ble/alerts/index.ts b/src/ble/alerts/index.ts
index 22b7ffc0..18d7641a 100644
--- a/src/ble/alerts/index.ts
+++ b/src/ble/alerts/index.ts
@@ -1,7 +1,8 @@
 // SPDX-License-Identifier: MIT
-// Copyright (c) 2022 The Pybricks Authors
+// Copyright (c) 2022-2023 The Pybricks Authors
 
 import { bluetoothNotAvailable } from './BluetoothNotAvailable';
+import { disconnected } from './Disconnected';
 import { missingService } from './MissingService';
 import { noGatt } from './NoGatt';
 import { noHub } from './NoHub';
@@ -11,6 +12,7 @@ import { oldFirmware } from './OldFirmware';
 // gathers all of the alert creation functions for passing up to the top level
 export default {
     bluetoothNotAvailable,
+    disconnected,
     missingService,
     noGatt,
     noHub,
diff --git a/src/ble/alerts/translations/en.json b/src/ble/alerts/translations/en.json
index 97c4da8b..3b12f341 100644
--- a/src/ble/alerts/translations/en.json
+++ b/src/ble/alerts/translations/en.json
@@ -29,5 +29,8 @@
         "flashFirmware": {
             "label": "Update Pybricks firmware"
         }
+    },
+    "disconnected": {
+        "message": "The hub is no longer connected. Please reconnect and try again."
     }
 }
diff --git a/src/hub/sagas.ts b/src/hub/sagas.ts
index 2bdc5d37..5c789ed5 100644
--- a/src/hub/sagas.ts
+++ b/src/hub/sagas.ts
@@ -1,5 +1,5 @@
 // SPDX-License-Identifier: MIT
-// Copyright (c) 2020-2022 The Pybricks Authors
+// Copyright (c) 2020-2023 The Pybricks Authors
 
 import {
     SagaGenerator,
@@ -326,9 +326,15 @@ function* handleDownloadAndRun(action: ReturnType<typeof downloadAndRun>): Gener
             console.error(err);
         }
 
-        yield* put(
-            alertsShowAlert('alerts', 'unexpectedError', { error: ensureError(err) }),
-        );
+        if (err instanceof DOMException && err.name === 'NetworkError') {
+            yield* put(alertsShowAlert('ble', 'disconnected'));
+        } else {
+            yield* put(
+                alertsShowAlert('alerts', 'unexpectedError', {
+                    error: ensureError(err),
+                }),
+            );
+        }
 
         yield* put(didFailToFinishDownload());
     }