diff --git a/TODO b/TODO
index 4170fa2a..b8c5350d 100644
--- a/TODO
+++ b/TODO
@@ -1,5 +1,13 @@
 Working TODO list:
 
+ - Cyclone hangs when creating a circular list. I believe this used to work:
+
+        cyclone> (define a (list 1 2))
+        ok
+        cyclone> a
+        (1 2)
+        cyclone> (set-cdr! a a)
+
  - Error handling
    need to perform much more error handling of input code. one of the biggest is to report if a function is passed the wrong number of arguments, as this will result in segfauls, bad transport errors, etc downstream if it is allowed.