diff --git a/packages/client/src/daemon-client.test.ts b/packages/client/src/daemon-client.test.ts
index a16d2e4be8..5089ce682f 100644
--- a/packages/client/src/daemon-client.test.ts
+++ b/packages/client/src/daemon-client.test.ts
@@ -2654,7 +2654,7 @@ test("foreground verification preserves a healthy socket and deduplicates simult
   expect(daemon.closesFromClient()).toEqual([]);
 });
 
-test("chunks extend the heartbeat deadline until silence causes two misses", async () => {
+test("chunks prevent heartbeat misses until silence causes two misses", async () => {
   useHeartbeatClock();
   const daemon = new FakeDaemon();
   daemon.daemonGoesSilent();
@@ -2685,9 +2685,9 @@ test("chunks extend the heartbeat deadline until silence causes two misses", asy
     daemon.receiveChunk(index === 0);
     expect(daemon.closesFromClient()).toEqual([]);
   }
-  // No complete message or pong has arrived, but chunks keep the ping alive.
-  expect(daemon.pingTimestamps()).toEqual(["0s"]);
-  await vi.advanceTimersByTimeAsync(15_000);
+  // No complete message or pong has arrived, but progress prevents misses.
+  expect(daemon.pingTimestamps()).toEqual(["0s", "25s"]);
+  await vi.advanceTimersByTimeAsync(25_000);
   expect(daemon.closesFromClient()).toEqual([]);
   await vi.advanceTimersByTimeAsync(25_000);
   expect(daemon.closesFromClient()).toEqual([{ code: 1001, reason: "Liveness check timed out" }]);
@@ -2716,8 +2716,41 @@ test("foreground preserves a multi-MB transfer with its pong queued behind chunk
     daemon.receiveChunk(index === 0);
     expect(daemon.closesFromClient()).toEqual([]);
   }
-  // No complete message or pong has arrived, but chunks keep the ping alive.
-  expect(daemon.pingTimestamps()).toEqual(["0s"]);
+  // No complete message or pong has arrived, but progress prevents misses.
+  expect(daemon.pingTimestamps()).toEqual(["0s", "25s"]);
+  daemon.finishTransfer();
+  await vi.advanceTimersByTimeAsync(30_000);
+  expect(client.getConnectionState()).toEqual({ status: "connected" });
+  expect(daemon.closesFromClient()).toEqual([]);
+});
+
+test("chunk progress beyond the daemon lease keeps sending heartbeat pings", async () => {
+  useHeartbeatClock();
+  const daemon = new FakeDaemon();
+  daemon.daemonGoesSilent();
+  const client = new DaemonClient({
+    url: "ws://test",
+    clientId: "long-download",
+    logger: noopLogger,
+    reconnect: { enabled: false },
+    transportFactory: () => daemon.transport,
+  });
+  clients.push(client);
+  const connection = client.connect();
+  daemon.openConnection();
+  await connection;
+  client.ensureConnected({ verify: true });
+  for (let index = 0; index < 12; index++) {
+    await vi.advanceTimersByTimeAsync(5_000);
+    daemon.receiveChunk(index === 0);
+    // Each completed window starts the next ping ten seconds later,
+    // even though the response and all queued pongs are still in flight.
+    const expected = ["0s"];
+    if (index >= 4) expected.push("25s");
+    if (index >= 9) expected.push("50s");
+    expect(daemon.pingTimestamps()).toEqual(expected);
+    expect(daemon.closesFromClient()).toEqual([]);
+  }
   daemon.finishTransfer();
   await vi.advanceTimersByTimeAsync(30_000);
   expect(client.getConnectionState()).toEqual({ status: "connected" });
diff --git a/packages/client/src/daemon-client.ts b/packages/client/src/daemon-client.ts
index 4bad95d31f..896d322a60 100644
--- a/packages/client/src/daemon-client.ts
+++ b/packages/client/src/daemon-client.ts
@@ -1295,7 +1295,7 @@ interface PingProbe {
   reject: (error: Error) => void;
   timeoutHandle: ReturnType<typeof setTimeout>;
   startedAt: number;
-  extendDeadline: () => void;
+  receivedActivity: boolean;
   // Whether a timeout on this ping should be recorded as a liveness failure. Only the
   // heartbeat sets this; a latency measurement never drives teardown, even when a
   // heartbeat tick shares (dedupes onto) an in-flight measurement ping.
@@ -1800,7 +1800,7 @@ export class DaemonClient {
 
   private recordTransportActivity(): void {
     this.consecutiveLivenessFailures = 0;
-    if (this.pingProbe?.drivesLivenessFailure) this.pingProbe.extendDeadline();
+    if (this.pingProbe) this.pingProbe.receivedActivity = true;
   }
 
   requireConnectedHosts(): void {
@@ -2588,7 +2588,9 @@ export class DaemonClient {
       this.pingProbe = null;
       const error = new PingTimeoutError(timeoutMs);
       probe.reject(error);
-      if (probe.drivesLivenessFailure) {
+      // Keep the deadline fixed so subsequent pings renew the daemon socket lease
+      // during a long download. Progress proves life even when its pong is queued.
+      if (probe.drivesLivenessFailure && !probe.receivedActivity) {
         this.recordLivenessFailure(toTimeoutError(error, "Liveness check", timeoutMs));
       }
     };
@@ -2597,10 +2599,7 @@ export class DaemonClient {
       resolve: (value) => resolveProbe?.(value),
       reject: (error) => rejectProbe?.(error),
       timeoutHandle: setTimeout(expire, timeoutMs),
-      extendDeadline: () => {
-        clearTimeout(probe.timeoutHandle);
-        probe.timeoutHandle = setTimeout(expire, timeoutMs);
-      },
+      receivedActivity: false,
       startedAt,
       drivesLivenessFailure: params.drivesLivenessFailure,
     };