Issue #3680: Reference cycles created through a dict, set or deque iterator did not get collected.
diff --git a/Misc/NEWS b/Misc/NEWS
index 9639b18..8ab8dd2 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -12,6 +12,9 @@
 Core and Builtins
 -----------------
 
+- Issue #3680: Reference cycles created through a dict, set or deque iterator
+  did not get collected.
+
 - Issue #4701: PyObject_Hash now implicitly calls PyType_Ready on types
   where the tp_hash and tp_dict slots are both NULL.