diff --git a/CHANGELOG.md b/CHANGELOG.md
index 7c20c0bc0c..d7bced776c 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -8,6 +8,12 @@ ENHANCEMENTS:
 
 * The "Failed to install provider" error message now includes the reason a provider could not be installed. [GH-31898]
 
+EXPERIMENTS:
+
+* Since its introduction the `yamlencode` function's documentation carried a warning that it was experimental. This predated our more formalized idea of language experiments and so wasn't guarded by an explicit opt-in, but the intention was to allow for small adjustments to its behavior if we learned it was producing invalid YAML in some cases, due to the relative complexity of the YAML specification.
+
+    From Terraform v1.4 onwards, `yamlencode` is no longer documented as experimental and is now subject to the Terraform v1.x Compatibility Promises. There are no changes to its previous behavior in v1.3 and so no special action is required when upgrading.
+
 ## Previous Releases
 
 For information on prior major and minor releases, see their changelogs: