diff --git a/CHANGES.md b/CHANGES.md
index 7d76a08419c..7880f65b556 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -59,6 +59,11 @@ symlink to `DIR` (see #3884).
 
 ### Enhancements
 
+[#3974](https://github.com/cylc/cylc-flow/pull/3974) - Template variables,
+both in set files and provided via the -s/--set command line options are
+now parsed using ast.literal_eval. This permits non-string data types,
+strings must now be quoted.
+
 [#3811](https://github.com/cylc/cylc-flow/pull/3811) - Move from cycle based
 to `n` distance dependency graph window node generation and pruning of the
 data-store (API/visual backing data). Ability to modify distance of live