--- a/src/backend/replication/syncrep.c
+++ b/src/backend/replication/syncrep.c
@@ -924,6 +924,7 @@ SyncRepUpdateSyncStandbysDefined(void)

         if (sync_standbys_defined != WalSndCtl->sync_standbys_defined)
         {
+               sleep(2);
                 LWLockAcquire(SyncRepLock, LW_EXCLUSIVE);

                 /*