diff --git a/nbd/server.c b/nbd/server.c
index b60ebc3ab6..3927f7789d 100644
--- a/nbd/server.c
+++ b/nbd/server.c
@@ -973,7 +973,8 @@ static int nbd_negotiate_meta_queries(NBDClient *client,
 {
     int ret;
     g_autofree char *export_name = NULL;
-    g_autofree bool *bitmaps = NULL;
+    /* Mark unused to work around https://bugs.llvm.org/show_bug.cgi?id=3888 */
+    g_autofree G_GNUC_UNUSED bool *bitmaps = NULL;
     NBDExportMetaContexts local_meta = {0};
     uint32_t nb_queries;
     size_t i;