diff --git a/CHANGELOG.md b/CHANGELOG.md
index c9a60007f..937a477ae 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -74,6 +74,7 @@
 - Onboarding: when OpenAI Codex OAuth is used, default to `openai-codex/gpt-5.2` and warn if the selected model lacks auth.
 - CLI: auto-migrate legacy config entries on command start (same behavior as gateway startup).
 - Gateway: add `gateway stop|restart` helpers and surface launchd/systemd/schtasks stop hints when the gateway is already running.
+- Cron/Heartbeat: enqueue cron system events in the resolved main session so heartbeats drain the right queue. Thanks @zats for PR #350.
 - Gateway: honor `agent.timeoutSeconds` for `chat.send` and share timeout defaults across chat/cron/auto-reply. Thanks @MSch for PR #229.
 - Auth: prioritize OAuth profiles but fall back to API keys when refresh fails; stored profiles now load without explicit auth order.
 - Auth/CLI: normalize provider ids and Z.AI aliases across auth profile ordering and models list/status. Thanks @mneves75 for PR #303.
diff --git a/src/gateway/server.ts b/src/gateway/server.ts
index 718f8d62a..d198f999b 100644
--- a/src/gateway/server.ts
+++ b/src/gateway/server.ts
@@ -32,7 +32,11 @@ import {
   deriveDefaultBridgePort,
   deriveDefaultCanvasHostPort,
 } from "../config/port-defaults.js";
-import { loadSessionStore, resolveStorePath } from "../config/sessions.js";
+import {
+  loadSessionStore,
+  resolveMainSessionKey,
+  resolveStorePath,
+} from "../config/sessions.js";
 import { runCronIsolatedAgentTurn } from "../cron/isolated-agent.js";
 import { appendCronRunLog, resolveCronRunLogPath } from "../cron/run-log.js";
 import { CronService } from "../cron/service.js";
@@ -689,7 +693,9 @@ export async function startGatewayServer(
     const cron = new CronService({
       storePath,
       cronEnabled,
-      enqueueSystemEvent,
+      enqueueSystemEvent: (text) => {
+        enqueueSystemEvent(text, { sessionKey: resolveMainSessionKey(cfg) });
+      },
       requestHeartbeatNow,
       runIsolatedAgentJob: async ({ job, message }) => {
         const runtimeConfig = loadConfig();