diff --git a/CHANGELOG.md b/CHANGELOG.md
index ee1adaf96cb..ff13f2f69cd 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,9 +4,20 @@
 
 ### Language
 
+*   **Breaking change:** Covariance of type variables used in super-interfaces
+    is now enforced (issue [35097][]).  For example, the following code was
+    previously accepted and will now be rejected:
+
+```dart
+class A<X> {};
+class B<X> extends A<void Function(X)> {};
+```
+
 * The identifier `async` can now be used in asynchronous and generator
   functions.
 
+[35097]: https://github.com/dart-lang/sdk/issues/35097
+
 ### Core libraries
 
 #### `dart:developer`