diff --git a/blockdev.c b/blockdev.c
index 43e0c4ddf2..ff5ee9ff7b 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -2846,6 +2846,8 @@ BlockDeviceInfoList *qmp_query_named_block_nodes(bool has_flat,
 
 XDbgBlockGraph *qmp_x_debug_query_block_graph(Error **errp)
 {
+    GRAPH_RDLOCK_GUARD_MAINLOOP();
+
     return bdrv_get_xdbg_block_graph(errp);
 }
 
diff --git a/include/block/block-global-state.h b/include/block/block-global-state.h
index 505a0d0c11..4d80b3d554 100644
--- a/include/block/block-global-state.h
+++ b/include/block/block-global-state.h
@@ -192,7 +192,7 @@ int bdrv_has_zero_init_1(BlockDriverState *bs);
 int bdrv_has_zero_init(BlockDriverState *bs);
 BlockDriverState *bdrv_find_node(const char *node_name);
 BlockDeviceInfoList *bdrv_named_nodes_list(bool flat, Error **errp);
-XDbgBlockGraph *bdrv_get_xdbg_block_graph(Error **errp);
+XDbgBlockGraph * GRAPH_RDLOCK bdrv_get_xdbg_block_graph(Error **errp);
 BlockDriverState *bdrv_lookup_bs(const char *device,
                                  const char *node_name,
                                  Error **errp);