diff --git a/packages/client/connection/tests/fixture.spec.ts b/packages/client/connection/tests/fixture.spec.ts
index b7d4d12e8d..5d64fa4682 100644
--- a/packages/client/connection/tests/fixture.spec.ts
+++ b/packages/client/connection/tests/fixture.spec.ts
@@ -264,7 +264,9 @@ describe('createFixtureApi', () => {
     await consuming
     if (!created.result.ok) throw new Error('create failed')
     const createdId = created.result.value.sessionId
-    expect(seen).toEqual([{ type: 'host/session-added', sessionId: createdId, blank: true, cwd: '/tmp/fixture' }])
+    expect(seen).toEqual([{
+      type: 'host/session-added', sessionId: createdId, createdAt: expect.any(Number), blank: true, cwd: '/tmp/fixture',
+    }])
     const list = await api.sessions.list(req({}))
     if (!list.result.ok) throw new Error('list failed')
     expect(list.result.value.items.some(s => s.sessionId === createdId)).toBe(true)
@@ -699,7 +701,9 @@ describe('createFixtureApi', () => {
     await consuming
     // The session lands with the workspace's path as cwd, and the account
     // write pushes the fresh workspace snapshot after session-added.
-    expect(seen[0]).toEqual({ type: 'host/session-added', sessionId: id, blank: true, cwd: '/tmp/fixture' })
+    expect(seen[0]).toEqual({
+      type: 'host/session-added', sessionId: id, createdAt: expect.any(Number), blank: true, cwd: '/tmp/fixture',
+    })
     expect(seen[1]).toMatchObject({
       type: 'host/workspace-changed',
       workspace: { workspaceId: 'fx-ws-fixture', sessionIds: [id, 'fx-alpha', 'fx-beta', 'fx-gamma'] },
@@ -728,7 +732,10 @@ describe('createFixtureApi', () => {
     expect(frames[0]).toMatchObject({
       type: 'host/workspace-changed', workspace: { sessionIds: [preallocated] },
     })
-    expect(frames[1]).toEqual({ type: 'host/session-added', sessionId: preallocated, blank: true, cwd: made.result.value.workspace.path })
+    expect(frames[1]).toEqual({
+      type: 'host/session-added', sessionId: preallocated, createdAt: expect.any(Number), blank: true,
+      cwd: made.result.value.workspace.path,
+    })
 
     const retried = await api.sessions.create(req({
       workspaceId: made.result.value.workspace.workspaceId,