diff --git a/include/spdlog/spdlog.h b/include/spdlog/spdlog.h
index 8b4c3099..fa8f6cf2 100644
--- a/include/spdlog/spdlog.h
+++ b/include/spdlog/spdlog.h
@@ -62,7 +62,8 @@ void set_formatter(formatter_ptr f);
 void set_level(level::level_enum log_level);
 
 
-// Turn on async mode and set the queue size for each async_logger.
+// Turn on async mode (off by default) and set the queue size for each async_logger.
+// effective only for loggers created after this call.
 // queue_size: size of queue (must be power of 2). The queue will pre allocate queue_size entries upon construction.
 // async_overflow_policy (optional):
 //     async_overflow_policy::block_retry (default policy, if queue is full, block until queue has room for the new log entry)