diff --git a/gdbstub/gdbstub_sys.c b/gdbstub/gdbstub_sys.c
index bd966b29..39322f23 100644
--- a/gdbstub/gdbstub_sys.c
+++ b/gdbstub/gdbstub_sys.c
@@ -258,7 +258,8 @@ static int wait_ack(struct msg *msg)
         ret = mq_receive(in_queue, (char *)msg, sizeof *msg, 0);
     } while (ret < 0 && errno == EAGAIN);
 
-    if (msg->type != MSG_TYPE_ACK) {
+    if (msg->type != MSG_TYPE_ACK
+        && msg->type != MSG_TYPE_BREAK) {
         fprintf(stderr, "wait_ack: unexpected msg.type %d\n", msg->type);
         return 1;
     }