diff --git a/src/agents/subagent-list.test.ts b/src/agents/subagent-list.test.ts
index a90acec76671..740a8ae2bb9a 100644
--- a/src/agents/subagent-list.test.ts
+++ b/src/agents/subagent-list.test.ts
@@ -12,7 +12,8 @@ import {
   resetSubagentRegistryForTests,
 } from "./subagent-registry.test-helpers.js";
 import type { SubagentRunRecord } from "./subagent-registry.types.js";
-import { STALE_UNENDED_SUBAGENT_RUN_MS } from "./subagent-run-liveness.js";
+
+const STALE_UNENDED_SUBAGENT_RUN_MS = 2 * 60 * 60 * 1_000;
 
 let testWorkspaceDir = os.tmpdir();
 
diff --git a/src/agents/subagent-registry-queries.test.ts b/src/agents/subagent-registry-queries.test.ts
index bbea5a7e7b6f..8e7ca835f404 100644
--- a/src/agents/subagent-registry-queries.test.ts
+++ b/src/agents/subagent-registry-queries.test.ts
@@ -12,7 +12,8 @@ import {
   shouldIgnorePostCompletionAnnounceForSessionFromRuns,
 } from "./subagent-registry-queries.js";
 import type { SubagentRunRecord } from "./subagent-registry.types.js";
-import { STALE_UNENDED_SUBAGENT_RUN_MS } from "./subagent-run-liveness.js";
+
+const STALE_UNENDED_SUBAGENT_RUN_MS = 2 * 60 * 60 * 1_000;
 
 function makeRun(overrides: Partial<SubagentRunRecord>): SubagentRunRecord {
   const runId = overrides.runId ?? "run-default";
diff --git a/src/agents/subagent-run-liveness.test.ts b/src/agents/subagent-run-liveness.test.ts
index ad9c58c96f7c..b18c0daef79c 100644
--- a/src/agents/subagent-run-liveness.test.ts
+++ b/src/agents/subagent-run-liveness.test.ts
@@ -5,10 +5,11 @@ import {
   isLiveUnendedSubagentRun,
   RECENT_ENDED_SUBAGENT_CHILD_SESSION_MS,
   isStaleUnendedSubagentRun,
-  STALE_UNENDED_SUBAGENT_RUN_MS,
   shouldKeepSubagentRunChildLink,
 } from "./subagent-run-liveness.js";
 
+const STALE_UNENDED_SUBAGENT_RUN_MS = 2 * 60 * 60 * 1_000;
+
 describe("subagent run liveness", () => {
   const now = Date.parse("2026-04-25T12:00:00Z");
 
diff --git a/src/agents/subagent-run-liveness.ts b/src/agents/subagent-run-liveness.ts
index 424504392773..d91c551de414 100644
--- a/src/agents/subagent-run-liveness.ts
+++ b/src/agents/subagent-run-liveness.ts
@@ -7,7 +7,7 @@ import type { SubagentRunRecord } from "./subagent-registry.types.js";
 import { resolveSubagentRunDurationMs } from "./subagent-run-timeout.js";
 import { getSubagentSessionStartedAt } from "./subagent-session-metrics.js";
 
-export const STALE_UNENDED_SUBAGENT_RUN_MS = 2 * 60 * 60 * 1_000;
+const STALE_UNENDED_SUBAGENT_RUN_MS = 2 * 60 * 60 * 1_000;
 export const RECENT_ENDED_SUBAGENT_CHILD_SESSION_MS = 30 * 60 * 1_000;
 const EXPLICIT_TIMEOUT_STALE_GRACE_MS = 60_000;
 const MIN_REALISTIC_RUN_TIMESTAMP_MS = Date.UTC(2020, 0, 1);