diff --git a/extensions/matrix/src/matrix/actions/verification.test.ts b/extensions/matrix/src/matrix/actions/verification.test.ts
index c7b96e2e6a1..d33d017736a 100644
--- a/extensions/matrix/src/matrix/actions/verification.test.ts
+++ b/extensions/matrix/src/matrix/actions/verification.test.ts
@@ -93,6 +93,16 @@ describe("matrix verification actions", () => {
     };
   }
 
+  function mockCrossSigningPublicationStatus(published = true) {
+    return {
+      masterKeyPublished: published,
+      published,
+      selfSigningKeyPublished: published,
+      userId: "@bot:example.org",
+      userSigningKeyPublished: published,
+    };
+  }
+
   it("points encryption guidance at the selected Matrix account", async () => {
     loadConfigMock.mockReturnValue({
       channels: {
@@ -346,12 +356,21 @@ describe("matrix verification actions", () => {
     };
     const confirmSas = vi.fn(async () => true);
     const getOwnDeviceVerificationStatus = vi.fn(async () => mockVerifiedOwnerStatus());
+    const getOwnCrossSigningPublicationStatus = vi.fn(async () =>
+      mockCrossSigningPublicationStatus(),
+    );
     const bootstrapOwnDeviceVerification = vi.fn(async () => ({
+      crossSigning: mockCrossSigningPublicationStatus(),
       success: true,
       verification: mockVerifiedOwnerStatus(),
     }));
     withStartedActionClientMock.mockImplementation(async (_opts, run) => {
-      return await run({ bootstrapOwnDeviceVerification, crypto, getOwnDeviceVerificationStatus });
+      return await run({
+        bootstrapOwnDeviceVerification,
+        crypto,
+        getOwnCrossSigningPublicationStatus,
+        getOwnDeviceVerificationStatus,
+      });
     });
 
     await expect(runMatrixSelfVerification({ confirmSas, timeoutMs: 500 })).resolves.toMatchObject({
@@ -372,6 +391,7 @@ describe("matrix verification actions", () => {
       allowAutomaticCrossSigningReset: false,
       strict: false,
     });
+    expect(getOwnCrossSigningPublicationStatus).not.toHaveBeenCalled();
     expect(getOwnDeviceVerificationStatus).not.toHaveBeenCalled();
   });
 
@@ -406,7 +426,11 @@ describe("matrix verification actions", () => {
       .fn()
       .mockResolvedValueOnce(mockUnverifiedOwnerStatus())
       .mockResolvedValueOnce(mockVerifiedOwnerStatus());
+    const getOwnCrossSigningPublicationStatus = vi.fn(async () =>
+      mockCrossSigningPublicationStatus(),
+    );
     const bootstrapOwnDeviceVerification = vi.fn(async () => ({
+      crossSigning: mockCrossSigningPublicationStatus(),
       success: true,
       verification: mockUnverifiedOwnerStatus(),
     }));
@@ -415,6 +439,7 @@ describe("matrix verification actions", () => {
       return await run({
         bootstrapOwnDeviceVerification,
         crypto,
+        getOwnCrossSigningPublicationStatus,
         getOwnDeviceVerificationStatus,
         trustOwnIdentityAfterSelfVerification,
       });
@@ -431,9 +456,73 @@ describe("matrix verification actions", () => {
     });
 
     expect(getOwnDeviceVerificationStatus).toHaveBeenCalledTimes(2);
+    expect(getOwnCrossSigningPublicationStatus).toHaveBeenCalledTimes(2);
     expect(trustOwnIdentityAfterSelfVerification).toHaveBeenCalledTimes(1);
   });
 
+  it("does not complete self-verification until cross-signing keys are published", async () => {
+    const requested = {
+      completed: false,
+      hasSas: false,
+      id: "verification-1",
+      phaseName: "requested",
+      transactionId: "tx-self",
+    };
+    const sas = {
+      ...requested,
+      hasSas: true,
+      phaseName: "started",
+      sas: {
+        decimal: [1, 2, 3],
+      },
+    };
+    const completed = {
+      ...sas,
+      completed: true,
+      phaseName: "done",
+    };
+    const crypto = {
+      confirmVerificationSas: vi.fn(async () => completed),
+      listVerifications: vi.fn(async () => [sas]),
+      requestVerification: vi.fn(async () => requested),
+      startVerification: vi.fn(async () => sas),
+    };
+    const getOwnDeviceVerificationStatus = vi.fn(async () => mockVerifiedOwnerStatus());
+    const getOwnCrossSigningPublicationStatus = vi
+      .fn()
+      .mockResolvedValueOnce(mockCrossSigningPublicationStatus(false))
+      .mockResolvedValueOnce(mockCrossSigningPublicationStatus(true));
+    const bootstrapOwnDeviceVerification = vi.fn(async () => ({
+      crossSigning: mockCrossSigningPublicationStatus(false),
+      success: false,
+      verification: mockVerifiedOwnerStatus(),
+    }));
+    const trustOwnIdentityAfterSelfVerification = vi.fn(async () => {});
+    withStartedActionClientMock.mockImplementation(async (_opts, run) => {
+      return await run({
+        bootstrapOwnDeviceVerification,
+        crypto,
+        getOwnCrossSigningPublicationStatus,
+        getOwnDeviceVerificationStatus,
+        trustOwnIdentityAfterSelfVerification,
+      });
+    });
+
+    await expect(
+      runMatrixSelfVerification({ confirmSas: vi.fn(async () => true), timeoutMs: 500 }),
+    ).resolves.toMatchObject({
+      completed: true,
+      deviceOwnerVerified: true,
+      ownerVerification: {
+        verified: true,
+      },
+    });
+
+    expect(getOwnDeviceVerificationStatus).toHaveBeenCalledTimes(2);
+    expect(getOwnCrossSigningPublicationStatus).toHaveBeenCalledTimes(2);
+    expect(trustOwnIdentityAfterSelfVerification).not.toHaveBeenCalled();
+  });
+
   it("waits for SAS data without restarting an already-started self-verification", async () => {
     const requested = {
       completed: false,
@@ -465,6 +554,7 @@ describe("matrix verification actions", () => {
       startVerification: vi.fn(),
     };
     const bootstrapOwnDeviceVerification = vi.fn(async () => ({
+      crossSigning: mockCrossSigningPublicationStatus(),
       success: true,
       verification: mockVerifiedOwnerStatus(),
     }));
@@ -472,6 +562,7 @@ describe("matrix verification actions", () => {
       return await run({
         bootstrapOwnDeviceVerification,
         crypto,
+        getOwnCrossSigningPublicationStatus: vi.fn(async () => mockCrossSigningPublicationStatus()),
         getOwnDeviceVerificationStatus: vi.fn(async () => mockVerifiedOwnerStatus()),
       });
     });
@@ -543,6 +634,7 @@ describe("matrix verification actions", () => {
     };
     const confirmSas = vi.fn(async () => true);
     const bootstrapOwnDeviceVerification = vi.fn(async () => ({
+      crossSigning: mockCrossSigningPublicationStatus(),
       success: true,
       verification: mockVerifiedOwnerStatus(),
     }));
@@ -550,6 +642,7 @@ describe("matrix verification actions", () => {
       return await run({
         bootstrapOwnDeviceVerification,
         crypto,
+        getOwnCrossSigningPublicationStatus: vi.fn(async () => mockCrossSigningPublicationStatus()),
         getOwnDeviceVerificationStatus: vi.fn(async () => mockVerifiedOwnerStatus()),
       });
     });
@@ -594,6 +687,7 @@ describe("matrix verification actions", () => {
       startVerification: vi.fn(async () => sas),
     };
     const bootstrapOwnDeviceVerification = vi.fn(async () => ({
+      crossSigning: mockCrossSigningPublicationStatus(),
       success: false,
       error: "Matrix room key backup is not trusted by this device",
       verification: mockVerifiedOwnerStatus(),
@@ -643,6 +737,7 @@ describe("matrix verification actions", () => {
       startVerification: vi.fn(async () => sas),
     };
     const bootstrapOwnDeviceVerification = vi.fn(async () => ({
+      crossSigning: mockCrossSigningPublicationStatus(false),
       success: false,
       error: "cross-signing identity is still not trusted",
       verification: mockUnverifiedOwnerStatus(),
@@ -651,6 +746,9 @@ describe("matrix verification actions", () => {
       return await run({
         bootstrapOwnDeviceVerification,
         crypto,
+        getOwnCrossSigningPublicationStatus: vi.fn(async () =>
+          mockCrossSigningPublicationStatus(false),
+        ),
         getOwnDeviceVerificationStatus: vi.fn(async () => mockUnverifiedOwnerStatus()),
       });
     });
diff --git a/extensions/matrix/src/matrix/actions/verification.ts b/extensions/matrix/src/matrix/actions/verification.ts
index 4a060a64705..2fc44470cbb 100644
--- a/extensions/matrix/src/matrix/actions/verification.ts
+++ b/extensions/matrix/src/matrix/actions/verification.ts
@@ -168,15 +168,21 @@ function formatMatrixOwnerVerificationDiagnostics(
   }, locally trusted: ${status.localVerified ? "yes" : "no"}`;
 }
 
-async function waitForMatrixOwnerVerificationStatus(params: {
+async function waitForMatrixSelfVerificationTrustStatus(params: {
   client: MatrixActionClient;
   timeoutMs: number;
 }): Promise<MatrixOwnDeviceVerificationStatus> {
   const startedAt = Date.now();
   let last: MatrixOwnDeviceVerificationStatus | undefined;
+  let crossSigningPublished = false;
   while (Date.now() - startedAt < params.timeoutMs) {
-    last = await params.client.getOwnDeviceVerificationStatus();
-    if (last.verified) {
+    const [status, crossSigning] = await Promise.all([
+      params.client.getOwnDeviceVerificationStatus(),
+      params.client.getOwnCrossSigningPublicationStatus(),
+    ]);
+    last = status;
+    crossSigningPublished = crossSigning.published;
+    if (last.verified && crossSigningPublished) {
       return last;
     }
     await sleep(Math.min(250, Math.max(25, params.timeoutMs - (Date.now() - startedAt))));
@@ -184,7 +190,7 @@ async function waitForMatrixOwnerVerificationStatus(params: {
   throw new Error(
     `Timed out waiting for Matrix self-verification to establish full Matrix identity trust for this device (${formatMatrixOwnerVerificationDiagnostics(
       last,
-    )}). Complete self-verification from another Matrix client, then check Matrix verification status for details.`,
+    )}, cross-signing keys published: ${crossSigningPublished ? "yes" : "no"}). Complete self-verification from another Matrix client, then check Matrix verification status for details.`,
   );
 }
 
@@ -215,12 +221,13 @@ async function completeMatrixSelfVerification(params: {
   if (!bootstrap.verification.verified) {
     await params.client.trustOwnIdentityAfterSelfVerification?.();
   }
-  const ownerVerification = bootstrap.verification.verified
-    ? bootstrap.verification
-    : await waitForMatrixOwnerVerificationStatus({
-        client: params.client,
-        timeoutMs: params.timeoutMs,
-      });
+  const ownerVerification =
+    bootstrap.verification.verified && bootstrap.crossSigning.published
+      ? bootstrap.verification
+      : await waitForMatrixSelfVerificationTrustStatus({
+          client: params.client,
+          timeoutMs: params.timeoutMs,
+        });
   return {
     ...params.completed,
     deviceOwnerVerified: ownerVerification.verified,