diff --git a/test/old/testdir/test_plugin_termdebug.vim b/test/old/testdir/test_plugin_termdebug.vim
index 860a639dc0..a3821c0606 100644
--- a/test/old/testdir/test_plugin_termdebug.vim
+++ b/test/old/testdir/test_plugin_termdebug.vim
@@ -57,6 +57,7 @@ endfunction
 packadd termdebug
 
 func Test_termdebug_basic()
+  let g:test_is_flaky = 1
   let bin_name = 'XTD_basic'
   let src_name = bin_name .. '.c'
   call s:generate_files(bin_name)