diff --git a/src/gateway/talk-realtime-relay.test.ts b/src/gateway/talk-realtime-relay.test.ts
index fbe12d2f04d..9065dfe570f 100644
--- a/src/gateway/talk-realtime-relay.test.ts
+++ b/src/gateway/talk-realtime-relay.test.ts
@@ -41,6 +41,22 @@ describe("talk realtime gateway relay", () => {
     };
   }
 
+  it("rejects session creation when relay expiry would exceed Date range", () => {
+    vi.useFakeTimers();
+    vi.setSystemTime(new Date(8_640_000_000_000_000));
+
+    expect(() =>
+      createTalkRealtimeRelaySession({
+        context: {} as never,
+        connId: "conn-1",
+        provider: createIdleRelayProvider(),
+        providerConfig: {},
+        instructions: "brief",
+        tools: [],
+      }),
+    ).toThrow("Realtime relay session expiry is outside the supported Date range");
+  });
+
   function createAbortableRelayRunFixture(provider = createIdleRelayProvider()) {
     const abortController = new AbortController();
     const broadcast = vi.fn();
diff --git a/src/gateway/talk-realtime-relay.ts b/src/gateway/talk-realtime-relay.ts
index b3df13e0662..1e5c0565a9c 100644
--- a/src/gateway/talk-realtime-relay.ts
+++ b/src/gateway/talk-realtime-relay.ts
@@ -1,6 +1,7 @@
 import { randomUUID } from "node:crypto";
 import type { OpenClawConfig } from "../config/types.js";
 import type { RealtimeVoiceProviderPlugin } from "../plugins/types.js";
+import { asDateTimestampMs, resolveExpiresAtMsFromDurationMs } from "../shared/number-coercion.js";
 import {
   REALTIME_VOICE_AGENT_CONSULT_TOOL_NAME,
   buildRealtimeVoiceAgentConsultWorkingResponse,
@@ -275,8 +276,13 @@ function closeRelaySession(session: RelaySession, reason: "completed" | "error")
 }
 
 function pruneExpiredRelaySessions(nowMs = Date.now()): void {
+  const validNowMs = asDateTimestampMs(nowMs);
+  if (validNowMs === undefined) {
+    return;
+  }
   for (const session of relaySessions.values()) {
-    if (nowMs > session.expiresAtMs) {
+    const expiresAtMs = asDateTimestampMs(session.expiresAtMs);
+    if (expiresAtMs === undefined || validNowMs > expiresAtMs) {
       closeRelaySession(session, "completed");
     }
   }
@@ -308,7 +314,10 @@ export function createTalkRealtimeRelaySession(
   enforceRelaySessionLimits(params.connId);
   const forceAgentConsultOnFinalTranscript = params.forceAgentConsultOnFinalTranscript === true;
   const relaySessionId = randomUUID();
-  const expiresAtMs = Date.now() + RELAY_SESSION_TTL_MS;
+  const expiresAtMs = resolveExpiresAtMsFromDurationMs(RELAY_SESSION_TTL_MS);
+  if (expiresAtMs === undefined) {
+    throw new Error("Realtime relay session expiry is outside the supported Date range");
+  }
   const talk = createTalkSessionController(
     {
       sessionId: relaySessionId,
@@ -688,7 +697,15 @@ function ensureRelayTurn(session: RelaySession): string {
 
 function getRelaySession(relaySessionId: string, connId: string): RelaySession {
   const session = relaySessions.get(relaySessionId);
-  if (!session || session.connId !== connId || Date.now() > session.expiresAtMs) {
+  const nowMs = asDateTimestampMs(Date.now());
+  const expiresAtMs = session ? asDateTimestampMs(session.expiresAtMs) : undefined;
+  if (
+    !session ||
+    session.connId !== connId ||
+    nowMs === undefined ||
+    expiresAtMs === undefined ||
+    nowMs > expiresAtMs
+  ) {
     if (session) {
       closeRelaySession(session, "completed");
     }