diff --git a/frontend/AGENTS.md b/frontend/AGENTS.md
index 8d3550a..3f0f1bc 100644
--- a/frontend/AGENTS.md
+++ b/frontend/AGENTS.md
@@ -74,6 +74,7 @@ frontend/src/
     ├── setup.ts
     ├── fixtures/websocket_events.json
     ├── api.test.ts
+    ├── useAirtimeTracking.test.ts
     ├── appFavorites.test.tsx
     ├── appStartupHash.test.tsx
     ├── contactAvatar.test.ts
diff --git a/frontend/src/hooks/useAirtimeTracking.ts b/frontend/src/hooks/useAirtimeTracking.ts
index 280e973..bee3406 100644
--- a/frontend/src/hooks/useAirtimeTracking.ts
+++ b/frontend/src/hooks/useAirtimeTracking.ts
@@ -152,6 +152,10 @@ export function useAirtimeTracking(
       }
     }
 
+    // If tracking was stopped while the request was in-flight (e.g. conversation
+    // switch called stopTracking), discard the stale response.
+    if (!baselineRef.current) return;
+
     if (telemetry) {
       const statsMessage = createLocalMessage(
         baseline.conversationId,
diff --git a/frontend/src/test/useAirtimeTracking.test.ts b/frontend/src/test/useAirtimeTracking.test.ts
new file mode 100644
index 0000000..f518f02
--- /dev/null
+++ b/frontend/src/test/useAirtimeTracking.test.ts
@@ -0,0 +1,126 @@
+import { act, renderHook } from '@testing-library/react';
+import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest';
+
+import { useAirtimeTracking } from '../hooks/useAirtimeTracking';
+import type { Message, TelemetryResponse } from '../types';
+
+function createTelemetry(overrides: Partial<TelemetryResponse> = {}): TelemetryResponse {
+  return {
+    pubkey_prefix: 'AABB',
+    battery_volts: 3.7,
+    tx_queue_len: 0,
+    noise_floor_dbm: -120,
+    last_rssi_dbm: -80,
+    last_snr_db: 10,
+    packets_received: 100,
+    packets_sent: 50,
+    airtime_seconds: 10,
+    rx_airtime_seconds: 5,
+    uptime_seconds: 3600,
+    sent_flood: 30,
+    sent_direct: 20,
+    recv_flood: 60,
+    recv_direct: 40,
+    flood_dups: 5,
+    direct_dups: 2,
+    full_events: 0,
+    clock_output: null,
+    neighbors: [],
+    acl: [],
+    ...overrides,
+  };
+}
+
+function createDeferred<T>() {
+  let resolve: (value: T | PromiseLike<T>) => void = () => {};
+  const promise = new Promise<T>((res) => {
+    resolve = res;
+  });
+  return { promise, resolve };
+}
+
+const mockRequestTelemetry = vi.fn<(...args: unknown[]) => Promise<TelemetryResponse>>();
+
+vi.mock('../api', () => ({
+  api: {
+    requestTelemetry: (...args: unknown[]) => mockRequestTelemetry(...args),
+  },
+}));
+
+describe('useAirtimeTracking stale poll guard', () => {
+  beforeEach(() => {
+    mockRequestTelemetry.mockReset();
+    vi.useFakeTimers();
+  });
+
+  afterEach(() => {
+    vi.useRealTimers();
+  });
+
+  it('discards poll response when tracking was stopped during in-flight request', async () => {
+    const setMessages = vi.fn<React.Dispatch<React.SetStateAction<Message[]>>>();
+
+    // Initial telemetry for dutycycle_start succeeds immediately
+    mockRequestTelemetry.mockResolvedValueOnce(createTelemetry());
+
+    const { result } = renderHook(() => useAirtimeTracking(setMessages));
+
+    // Start tracking
+    await act(async () => {
+      await result.current.handleAirtimeCommand('dutycycle_start', 'repeater_a');
+    });
+
+    // setMessages was called with the start message
+    const startCallCount = setMessages.mock.calls.length;
+    expect(startCallCount).toBeGreaterThanOrEqual(1);
+
+    // Set up a deferred telemetry response for the poll
+    const deferred = createDeferred<TelemetryResponse>();
+    mockRequestTelemetry.mockReturnValueOnce(deferred.promise);
+
+    // Advance timer to trigger the 5-minute poll
+    act(() => {
+      vi.advanceTimersByTime(5 * 60 * 1000);
+    });
+
+    // Poll is now in-flight. Stop tracking (simulates conversation switch).
+    act(() => {
+      result.current.stopTracking();
+    });
+
+    // Resolve the stale telemetry response
+    await act(async () => {
+      deferred.resolve(createTelemetry({ uptime_seconds: 7200 }));
+    });
+
+    // setMessages should NOT have been called with the stale poll result
+    // Only the start message calls should exist
+    expect(setMessages.mock.calls.length).toBe(startCallCount);
+  });
+
+  it('appends poll result when tracking is still active', async () => {
+    const setMessages = vi.fn<React.Dispatch<React.SetStateAction<Message[]>>>();
+
+    // Initial telemetry for dutycycle_start
+    mockRequestTelemetry.mockResolvedValueOnce(createTelemetry());
+
+    const { result } = renderHook(() => useAirtimeTracking(setMessages));
+
+    await act(async () => {
+      await result.current.handleAirtimeCommand('dutycycle_start', 'repeater_a');
+    });
+
+    const startCallCount = setMessages.mock.calls.length;
+
+    // Set up poll response
+    mockRequestTelemetry.mockResolvedValueOnce(createTelemetry({ uptime_seconds: 7200 }));
+
+    // Advance timer to trigger the 5-minute poll
+    await act(async () => {
+      vi.advanceTimersByTime(5 * 60 * 1000);
+    });
+
+    // setMessages SHOULD have been called with the poll result
+    expect(setMessages.mock.calls.length).toBeGreaterThan(startCallCount);
+  });
+});