diff --git a/.kiro/specs/ha-heartbeat-liveness/tasks.md b/.kiro/specs/ha-heartbeat-liveness/tasks.md
index 6d74eec..b63389e 100644
--- a/.kiro/specs/ha-heartbeat-liveness/tasks.md
+++ b/.kiro/specs/ha-heartbeat-liveness/tasks.md
@@ -79,7 +79,7 @@
   - _Boundary: ha.c unit tests_
   - _Depends: 2.2_
 
-- [ ] 4.3 Integration test: 3-node cold start — no false RDHUP loops and race elimination
+- [x] 4.3 Integration test: 3-node cold start — no false RDHUP loops and race elimination
   - Deploy 3-node cluster (ctrl-1 has config, ctrl-2/3 tag=0); verify ctrl-1 elects PRIMARY
   - Verify ctrl-2/3 receive ctrlhello, set `last_activity`, and do NOT trigger RDHUP before `heartbeat_timeout_ms` elapses from ctrlhello
   - Verify cluster is stable for 60s with no `hb_timeout_thread` log entries (thread removed) and no RDHUP false-positive entries
@@ -87,7 +87,7 @@
   - _Requirements: 1.3, 1.4, 4.1, 4.2, 4.3, 5.1, 5.3_
   - _Depends: 3.1, 3.2_
 
-- [ ] 4.4 Integration test: primary crash triggers failover within timeout window
+- [x] 4.4 Integration test: primary crash triggers failover within timeout window
   - Start 3-node cluster; verify ctrl-1 PRIMARY and cluster stable
   - SIGKILL ctrl-1; verify ctrl-2 or ctrl-3 detects silence within `heartbeat_timeout_ms`; promotes to PRIMARY via RDHUP path
   - Verify promoted primary serves traffic; verify no infinite RDHUP loop
diff --git a/src/controller/ha.c b/src/controller/ha.c
index 4f94f7a..4d6e7c0 100644
--- a/src/controller/ha.c
+++ b/src/controller/ha.c
@@ -434,6 +434,12 @@ static void raft_cb_become_leader(void *ctx, uint64_t term)
 #else
         ha_send_ctrlhello_to_all_standbys(c);
 #endif
+        /* Start primary heartbeat immediately in COMMITTING so standbys receive
+         * NOP during the committing window and their liveness poll does not fire.
+         * ha_start_primary_heartbeat is also called in ha_promote_to_primary;
+         * the idempotency guard (role check at fn top) prevents double-arming. */
+        ha_start_primary_heartbeat(c);
+
         /* Arm committing timeout watchdog */
         committing_timeout_ctx_t *ct = calloc(1, sizeof(*ct));
         if (ct) {