diff --git a/TODO b/TODO
index 7260f197..a0d72143 100644
--- a/TODO
+++ b/TODO
@@ -4,5 +4,6 @@ Initiatives:
 - r7rs missing features
 - srfi 18 - conditional vars
 - more complex threading examples
+- test on a 64-bit platform/vm
 - online docs via read-the-docs
 - api documentation