diff --git a/runtime/lua/vim/diagnostic.lua b/runtime/lua/vim/diagnostic.lua
index 172bd867c7..98dbe0779b 100644
--- a/runtime/lua/vim/diagnostic.lua
+++ b/runtime/lua/vim/diagnostic.lua
@@ -1426,6 +1426,7 @@ function M.reset(namespace, bufnr)
     vim.api.nvim_exec_autocmds('DiagnosticChanged', {
       modeline = false,
       buffer = iter_bufnr,
+      data = { diagnostics = {} },
     })
   end
 end