diff --git a/TODO b/TODO
index 9ed12787..5b7b30b2 100644
--- a/TODO
+++ b/TODO
@@ -9,5 +9,6 @@ Waf 1.9
 * Use relative paths in apply_incpaths (and absolute ones when paths cross drives)
 * Provide a more efficient ConfigSet implementation
 * Ensure _cache.py are valid python files
+* One task.idx per task node
 * Other issues listed on https://github.com/waf-project/waf/issues