diff --git a/src/sagas/flash-firmware.test.ts b/src/sagas/flash-firmware.test.ts
index f0e95a85..a92911f0 100644
--- a/src/sagas/flash-firmware.test.ts
+++ b/src/sagas/flash-firmware.test.ts
@@ -40,6 +40,7 @@ import {
 } from '../actions/lwp3-bootloader';
 import { didCompile, didFailToCompile } from '../actions/mpy';
 import { HubType, Result } from '../protocols/lwp3-bootloader';
+import { BootloaderConnectionState } from '../reducers/bootloader';
 import { createCountFunc } from '../utils/iter';
 import flashFirmware from './flash-firmware';
 
@@ -86,6 +87,9 @@ describe('flashFirmware', () => {
             let action = await saga.take();
             expect(action).toEqual(connect());
 
+            saga.setState({
+                bootloader: { connection: BootloaderConnectionState.Connected },
+            });
             saga.put(didConnect());
 
             // then find out what kind of hub it is
@@ -278,6 +282,9 @@ describe('flashFirmware', () => {
             let action = await saga.take();
             expect(action).toEqual(connect());
 
+            saga.setState({
+                bootloader: { connection: BootloaderConnectionState.Connected },
+            });
             saga.put(didConnect());
 
             // then find out what kind of hub it is
@@ -289,6 +296,9 @@ describe('flashFirmware', () => {
 
             // hub disconnects before replying
 
+            saga.setState({
+                bootloader: { connection: BootloaderConnectionState.Disconnected },
+            });
             saga.put(didDisconnect());
 
             // should get a failure to start
@@ -338,6 +348,9 @@ describe('flashFirmware', () => {
             let action = await saga.take();
             expect(action).toEqual(connect());
 
+            saga.setState({
+                bootloader: { connection: BootloaderConnectionState.Connected },
+            });
             saga.put(didConnect());
 
             // then find out what kind of hub it is
@@ -417,6 +430,9 @@ describe('flashFirmware', () => {
             action = await saga.take();
             expect(action).toEqual(connect());
 
+            saga.setState({
+                bootloader: { connection: BootloaderConnectionState.Connected },
+            });
             saga.put(didConnect());
 
             // then find out what kind of hub it is
@@ -526,7 +542,10 @@ describe('flashFirmware', () => {
                 nextMessageId: createCountFunc(),
             });
 
-            saga.setState({ settings: { flashCurrentProgram: false } });
+            saga.setState({
+                bootloader: { connection: BootloaderConnectionState.Disconnected },
+                settings: { flashCurrentProgram: false },
+            });
 
             // saga is triggered by this action
 
@@ -571,7 +590,10 @@ describe('flashFirmware', () => {
                 nextMessageId: createCountFunc(),
             });
 
-            saga.setState({ settings: { flashCurrentProgram: false } });
+            saga.setState({
+                bootloader: { connection: BootloaderConnectionState.Disconnected },
+                settings: { flashCurrentProgram: false },
+            });
 
             // saga is triggered by this action
 
@@ -636,6 +658,12 @@ describe('flashFirmware', () => {
                 }
             `);
 
+            // this triggers a failure
+
+            saga.setState({
+                bootloader: { connection: BootloaderConnectionState.Disconnected },
+            });
+
             saga.put(didFailToCompile(['test']));
 
             // compiler error should trigger firmware flash failure
@@ -691,6 +719,10 @@ describe('flashFirmware', () => {
                 }
             `);
 
+            saga.setState({
+                bootloader: { connection: BootloaderConnectionState.Disconnected },
+            });
+
             const mpySize = 20;
             const mpyBinaryData = new Uint8Array(mpySize);
             saga.put(didCompile(mpyBinaryData));
@@ -749,6 +781,10 @@ describe('flashFirmware', () => {
                 }
             `);
 
+            saga.setState({
+                bootloader: { connection: BootloaderConnectionState.Disconnected },
+            });
+
             const mpySize = 20;
             const mpyBinaryData = new Uint8Array(mpySize);
             saga.put(didCompile(mpyBinaryData));
@@ -810,6 +846,9 @@ describe('flashFirmware', () => {
         let action = await saga.take();
         expect(action).toEqual(connect());
 
+        saga.setState({
+            bootloader: { connection: BootloaderConnectionState.Connected },
+        });
         saga.put(didConnect());
 
         // then find out what kind of hub it is
diff --git a/src/sagas/flash-firmware.ts b/src/sagas/flash-firmware.ts
index 29e90597..5c2cb0f3 100644
--- a/src/sagas/flash-firmware.ts
+++ b/src/sagas/flash-firmware.ts
@@ -63,6 +63,7 @@ import {
 import * as notification from '../actions/notification';
 import { MaxProgramFlashSize } from '../protocols/lwp3-bootloader';
 import { RootState } from '../reducers';
+import { BootloaderConnectionState } from '../reducers/bootloader';
 import { defined, maybe } from '../utils';
 import { fmod, sumComplement32 } from '../utils/math';
 
@@ -72,14 +73,33 @@ const firmwareZipMap = new Map<HubType, string>([
     [HubType.MoveHub, moveHubZip],
 ]);
 
+/**
+ * Disconnects the BLE if we are connected and cancels the task (including the
+ * parent task).
+ */
+function* disconnectAndCancel(): SagaGenerator<never> {
+    const connection = yield* select((s: RootState) => s.bootloader.connection);
+
+    if (connection === BootloaderConnectionState.Connected) {
+        yield* put(disconnect());
+    }
+
+    yield* cancel();
+
+    // HACK: cancel effect doesn't return, so we need this to make typescript
+    // happy about the never return type.
+
+    // istanbul ignore next: not reachable
+    throw undefined;
+}
+
 function* waitForDidRequest(id: number): SagaGenerator<BootloaderDidRequestAction> {
     const request = yield* take<BootloaderDidRequestAction>(
         (a: Action) => a.type === BootloaderDidRequestType && a.id === id,
     );
     if (request.err) {
         yield* put(didFailToFinish(FailToFinishReasonType.BleError, request.err));
-        yield* put(disconnect());
-        yield* cancel();
+        yield* disconnectAndCancel();
     }
 
     return request;
@@ -103,16 +123,14 @@ function* waitForResponse<T extends BootloaderResponseAction>(
 
     if (timedOut) {
         yield* put(didFailToFinish(FailToFinishReasonType.TimedOut));
-        yield* put(disconnect());
-        yield* cancel();
+        yield* disconnectAndCancel();
     }
 
     if (error) {
         yield* put(
             didFailToFinish(FailToFinishReasonType.HubError, HubError.UnknownCommand),
         );
-        yield* put(disconnect());
-        cancel();
+        yield* disconnectAndCancel();
     }
 
     defined(response);
@@ -150,7 +168,7 @@ function* loadFirmware(
         } else {
             yield* put(didFailToFinish(FailToFinishReasonType.Unknown, readerErr));
         }
-        yield* cancel();
+        yield* disconnectAndCancel();
     }
 
     defined(reader);
@@ -171,7 +189,7 @@ function* loadFirmware(
                 MetadataProblem.NotSupported,
             ),
         );
-        yield* cancel();
+        yield* disconnectAndCancel();
     }
 
     yield* put(compile(program, metadata['mpy-cross-options']));
@@ -182,7 +200,7 @@ function* loadFirmware(
 
     if (mpyFail) {
         yield* put(didFailToFinish(FailToFinishReasonType.FailedToCompile));
-        yield* cancel();
+        yield* disconnectAndCancel();
     }
 
     defined(mpy);
@@ -196,7 +214,7 @@ function* loadFirmware(
 
     if (firmware.length > metadata['max-firmware-size']) {
         yield* put(didFailToFinish(FailToFinishReasonType.FirmwareSize));
-        yield* cancel();
+        yield* disconnectAndCancel();
     }
 
     firmware.set(firmwareBase);
@@ -211,7 +229,7 @@ function* loadFirmware(
                 MetadataProblem.NotSupported,
             ),
         );
-        yield* cancel();
+        yield* disconnectAndCancel();
     }
 
     firmwareView.setUint32(
@@ -236,7 +254,7 @@ function* disconnectMonitor(): SagaGenerator<void> {
 
     if (disconnected) {
         yield* put(didFailToFinish(FailToFinishReasonType.Disconnected));
-        yield* cancel();
+        yield* disconnectAndCancel();
     }
 }