diff --git a/server/protocol.c b/server/protocol.c
index ac6eb2c..d406dc8 100644
--- a/server/protocol.c
+++ b/server/protocol.c
@@ -503,6 +503,9 @@ send_structured_reply_block_status (struct connection *conn,
   if (blocks == NULL)
     return connection_set_status (conn, -1);
 
+  nr_blocks = 32;
+  blocks[0].length = htobe32 (4096);
+
   reply.magic = htobe32 (NBD_STRUCTURED_REPLY_MAGIC);
   reply.handle = handle;
   reply.flags = htobe16 (NBD_REPLY_FLAG_DONE);
@@ -526,7 +529,7 @@ send_structured_reply_block_status (struct connection *conn,
 
   /* Send each block descriptor. */
   for (i = 0; i < nr_blocks; ++i) {
-    r = conn->send (conn, &blocks[i], sizeof blocks[i]);
+    r = conn->send (conn, &blocks[0], sizeof blocks[0]);
     if (r == -1) {
       nbdkit_error ("write reply: %s: %m", name_of_nbd_cmd (cmd));
       return connection_set_status (conn, -1);