diff --git a/packages/web/src/stores/spaceStore.deletedUser.test.ts b/packages/web/src/stores/spaceStore.deletedUser.test.ts
new file mode 100644
index 00000000..383aff3b
--- /dev/null
+++ b/packages/web/src/stores/spaceStore.deletedUser.test.ts
@@ -0,0 +1,58 @@
+import { describe, it, expect, beforeEach, vi } from 'vitest';
+
+vi.mock('../audio/AudioManager', () => ({
+  AudioManager: {
+    getInstance: vi.fn().mockReturnValue({
+      setOutputDevice: vi.fn(),
+      setVolume: vi.fn(),
+    }),
+  },
+}));
+
+vi.mock('./instanceStore', () => ({
+  useInstanceStore: Object.assign(
+    (selector: (s: unknown) => unknown) => selector({ instances: [], _autoConnectDone: true }),
+    {
+      getState: () => ({ instances: [], _autoConnectDone: true }),
+      setState: vi.fn(),
+      subscribe: vi.fn(),
+    }
+  ),
+}));
+
+vi.mock('./authStore', () => ({
+  useAuthStore: Object.assign(
+    (selector: (s: unknown) => unknown) => selector({ user: null, token: null }),
+    {
+      getState: () => ({ user: null, token: null }),
+      setState: vi.fn(),
+      subscribe: vi.fn(),
+    }
+  ),
+}));
+
+import { useSpaceStore } from './spaceStore';
+import type { DmChannel, User } from '@backspace/shared';
+
+describe('updateUserEverywhere → DM member patch (drives the live Deleted-User update)', () => {
+  beforeEach(() => {
+    useSpaceStore.setState({
+      dmChannels: [{
+        id: 'd1', ownerId: null, createdAt: 0,
+        members: [
+          { id: 'me', username: 'me' } as User,
+          { id: 'partner', username: 'partner', displayName: 'Partner', isDeleted: false } as User,
+        ],
+      } as DmChannel],
+    });
+  });
+
+  it('rewrites the matching member to the sanitized deleted user', () => {
+    const deleted = { id: 'partner', username: 'Deleted User', displayName: null, isDeleted: true } as User;
+    useSpaceStore.getState().updateUserEverywhere(deleted);
+    const member = useSpaceStore.getState().dmChannels[0].members.find(m => m.id === 'partner')!;
+    expect(member.username).toBe('Deleted User');
+    expect(member.isDeleted).toBe(true);
+    expect(member.displayName).toBeNull();
+  });
+});
diff --git a/packages/web/src/utils/dmFormatters.test.ts b/packages/web/src/utils/dmFormatters.test.ts
index f7a4171d..ecec5236 100644
--- a/packages/web/src/utils/dmFormatters.test.ts
+++ b/packages/web/src/utils/dmFormatters.test.ts
@@ -383,6 +383,19 @@ describe('formatDmInputLabel', () => {
   });
 });
 
+describe('deleted 1-on-1 partner', () => {
+  const me: User = { id: 'me', username: 'me', displayName: 'Me' } as User;
+  const deleted: User = { id: 'x', username: 'Deleted User', displayName: null, isDeleted: true } as User;
+  const dm = { id: 'd', ownerId: null, members: [me, deleted], createdAt: 0 } as unknown as DmChannel;
+
+  it('header shows Deleted User', () => {
+    expect(formatDmHeaderName(dm, me)).toBe('Deleted User');
+  });
+  it('input label points at Deleted User', () => {
+    expect(formatDmInputLabel(dm, me)).toBe('@Deleted User');
+  });
+});
+
 describe('formatDmSidebarPreview — icon_changed system message', () => {
   it('happy path → "<actor> updated the group icon"', () => {
     const dm = makeGroupDm({