diff --git a/CHANGELOG.md b/CHANGELOG.md
index 73f28fb5d4e..d2d72019154 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,6 +5,11 @@ project adheres to [Semantic Versioning](http://semver.org/).
 
 ## Unreleased
 
+### CLI
+
+- `opa exec`: This command never supported "pretty" formatting (`--format=pretty` or `-f pretty`), only `json`. Passing `pretty` is now invalid.
+  Note that the flag is now unnecessary, but it's kept so existing calls like `opa exec -fjson ...` remain valid.
+
 ## 0.67.1
 
 This is a bug fix release addressing the following issue: