diff --git a/CHANGELOG.md b/CHANGELOG.md
index 760bab5ea93..8c85d61b44b 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -82,7 +82,7 @@ Docs: https://docs.openclaw.ai
 - Providers/Mistral: send `reasoning_effort` for `mistral/mistral-small-latest` (Mistral Small 4) with thinking-level mapping, and mark the catalog entry as reasoning-capable so adjustable reasoning matches Mistral’s Chat Completions API. (#62162) Thanks @neeravmakwana.
 - OpenAI TTS/Groq: send `wav` to Groq-compatible speech endpoints, honor explicit `responseFormat` overrides on OpenAI-compatible paths, and only mark voice-note output as voice-compatible when the actual format is `opus`. (#62233) Thanks @neeravmakwana.
 - BlueBubbles/network: respect explicit private-network opt-out for loopback and private `serverUrl` values across account resolution, status probes, monitor startup, and attachment downloads, while keeping public-host attachment hostname pinning intact. (#59373) Thanks @jpreagan.
-
+- Agents/heartbeat: keep heartbeat runs pinned to the main session so active subagent transcripts are not overwritten by heartbeat status messages. (#61803) thanks @100yenadmin.
 ## 2026.4.5
 
 ### Breaking
diff --git a/src/infra/heartbeat-runner.ts b/src/infra/heartbeat-runner.ts
index 753c9b31fb3..11390af43a4 100644
--- a/src/infra/heartbeat-runner.ts
+++ b/src/infra/heartbeat-runner.ts
@@ -44,6 +44,7 @@ import { CommandLane } from "../process/lanes.js";
 import {
   isSubagentSessionKey,
   normalizeAgentId,
+  parseAgentSessionKey,
   resolveAgentIdFromSessionKey,
   toAgentStoreSessionKey,
 } from "../routing/session-key.js";
@@ -592,7 +593,11 @@ export async function runHeartbeatOnce(opts: {
 }): Promise<HeartbeatRunResult> {
   const cfg = opts.cfg ?? loadConfig();
   const explicitAgentId = typeof opts.agentId === "string" ? opts.agentId.trim() : "";
-  const agentId = normalizeAgentId(explicitAgentId || resolveDefaultAgentId(cfg));
+  const forcedSessionAgentId =
+    explicitAgentId.length > 0 ? undefined : parseAgentSessionKey(opts.sessionKey)?.agentId;
+  const agentId = normalizeAgentId(
+    explicitAgentId || forcedSessionAgentId || resolveDefaultAgentId(cfg),
+  );
   const heartbeat = opts.heartbeat ?? resolveHeartbeatConfig(cfg, agentId);
   if (!areHeartbeatsEnabled()) {
     return { status: "skipped", reason: "disabled" };