diff --git a/src/main/main.c b/src/main/main.c
index 1e6af642b..b15cc9746 100644
--- a/src/main/main.c
+++ b/src/main/main.c
@@ -1464,6 +1464,10 @@ int re_thread_async_init(uint16_t workers)
 		return EINVAL;
 	}
 
+	struct btrace bt;
+	btrace(&bt);
+	DEBUG_WARNING("ASYNC_INIT %H\n", btrace_println, &bt);
+
 	if (re->async)
 		return EALREADY;