diff --git a/block/nbd-client.c b/block/nbd-client.c
index 76e9ca3abe..fc5b7eda8e 100644
--- a/block/nbd-client.c
+++ b/block/nbd-client.c
@@ -992,10 +992,16 @@ int nbd_client_init(BlockDriverState *bs,
         logout("Failed to negotiate with the NBD server\n");
         return ret;
     }
+    if (x_dirty_bitmap && !client->info.base_allocation) {
+        error_setg(errp, "requested x-dirty-bitmap %s not found",
+                   x_dirty_bitmap);
+        ret = -EINVAL;
+        goto fail;
+    }
     if (client->info.flags & NBD_FLAG_READ_ONLY) {
         ret = bdrv_apply_auto_read_only(bs, "NBD export is read-only", errp);
         if (ret < 0) {
-            return ret;
+            goto fail;
         }
     }
     if (client->info.flags & NBD_FLAG_SEND_FUA) {
@@ -1024,4 +1030,17 @@ int nbd_client_init(BlockDriverState *bs,
 
     logout("Established connection with NBD server\n");
     return 0;
+
+ fail:
+    /*
+     * We have connected, but must fail for other reasons. The
+     * connection is still blocking; send NBD_CMD_DISC as a courtesy
+     * to the server.
+     */
+    {
+        NBDRequest request = { .type = NBD_CMD_DISC };
+
+        nbd_send_request(client->ioc ?: QIO_CHANNEL(sioc), &request);
+        return ret;
+    }
 }
diff --git a/nbd/server.c b/nbd/server.c
index dc04513de7..7af0ddffb2 100644
--- a/nbd/server.c
+++ b/nbd/server.c
@@ -978,6 +978,7 @@ static int nbd_negotiate_meta_queries(NBDClient *client,
     if (client->opt == NBD_OPT_LIST_META_CONTEXT && !nb_queries) {
         /* enable all known contexts */
         meta->base_allocation = true;
+        meta->bitmap = !!meta->exp->export_bitmap;
     } else {
         for (i = 0; i < nb_queries; ++i) {
             ret = nbd_negotiate_meta_query(client, meta, errp);