diff --git a/test/CreateCrossSigning-test.ts b/test/CreateCrossSigning-test.ts
new file mode 100644
index 0000000000..1fc64ddcbc
--- /dev/null
+++ b/test/CreateCrossSigning-test.ts
@@ -0,0 +1,96 @@
+/*
+Copyright 2024 New Vector Ltd.
+Copyright 2018-2022 The Matrix.org Foundation C.I.C.
+
+SPDX-License-Identifier: AGPL-3.0-only OR GPL-3.0-only
+Please see LICENSE files in the repository root for full details.
+*/
+
+import { MatrixClient, MatrixError } from "matrix-js-sdk/src/matrix";
+import { mocked } from "jest-mock";
+
+import { createCrossSigning } from "../src/CreateCrossSigning";
+import { createTestClient } from "./test-utils";
+import Modal from "../src/Modal";
+
+describe("CreateCrossSigning", () => {
+    let client: MatrixClient;
+
+    beforeEach(() => {
+        client = createTestClient();
+    });
+
+    afterEach(() => {});
+
+    it("should call bootstrapCrossSigning with an authUploadDeviceSigningKeys function", async () => {
+        await createCrossSigning(client, false, "password");
+
+        expect(client.getCrypto()?.bootstrapCrossSigning).toHaveBeenCalledWith({
+            authUploadDeviceSigningKeys: expect.any(Function),
+        });
+    });
+
+    it("should upload with password auth if possible", async () => {
+        client.uploadDeviceSigningKeys = jest.fn().mockRejectedValueOnce(
+            new MatrixError({
+                flows: [
+                    {
+                        stages: ["m.login.password"],
+                    },
+                ],
+            }),
+        );
+
+        await createCrossSigning(client, false, "password");
+
+        const { authUploadDeviceSigningKeys } = mocked(client.getCrypto()!).bootstrapCrossSigning.mock.calls[0][0];
+
+        const makeRequest = jest.fn();
+        await authUploadDeviceSigningKeys!(makeRequest);
+        expect(makeRequest).toHaveBeenCalledWith({
+            type: "m.login.password",
+            identifier: {
+                type: "m.id.user",
+                user: client.getUserId(),
+            },
+            password: "password",
+        });
+    });
+
+    it("should attempt to upload keys without auth if using token login", async () => {
+        await createCrossSigning(client, true, undefined);
+
+        const { authUploadDeviceSigningKeys } = mocked(client.getCrypto()!).bootstrapCrossSigning.mock.calls[0][0];
+
+        const makeRequest = jest.fn();
+        await authUploadDeviceSigningKeys!(makeRequest);
+        expect(makeRequest).toHaveBeenCalledWith({});
+    });
+
+    it("should prompt user if password upload not possible", async () => {
+        const createDialog = jest.spyOn(Modal, "createDialog").mockReturnValue({
+            finished: Promise.resolve([true]),
+            close: jest.fn(),
+        });
+        jest.mock;
+
+        client.uploadDeviceSigningKeys = jest.fn().mockRejectedValueOnce(
+            new MatrixError({
+                flows: [
+                    {
+                        stages: ["dummy.mystery_flow_nobody_knows"],
+                    },
+                ],
+            }),
+        );
+
+        await createCrossSigning(client, false, "password");
+
+        const { authUploadDeviceSigningKeys } = mocked(client.getCrypto()!).bootstrapCrossSigning.mock.calls[0][0];
+
+        const makeRequest = jest.fn();
+        await authUploadDeviceSigningKeys!(makeRequest);
+        expect(makeRequest).not.toHaveBeenCalledWith();
+        expect(createDialog).toHaveBeenCalled();
+    });
+});
diff --git a/test/test-utils/test-utils.ts b/test/test-utils/test-utils.ts
index ebfc6b221b..fac0a51e61 100644
--- a/test/test-utils/test-utils.ts
+++ b/test/test-utils/test-utils.ts
@@ -132,6 +132,7 @@ export function createTestClient(): MatrixClient {
             isEncryptionEnabledInRoom: jest.fn(),
             getVerificationRequestsToDeviceInProgress: jest.fn().mockReturnValue([]),
             setDeviceIsolationMode: jest.fn(),
+            bootstrapCrossSigning: jest.fn(),
         }),
 
         getPushActionsForEvent: jest.fn(),