diff --git a/api/API_VERSIONING.md b/api/API_VERSIONING.md
index f1bf6a8912e08..f864619602a1d 100644
--- a/api/API_VERSIONING.md
+++ b/api/API_VERSIONING.md
@@ -68,7 +68,8 @@ experience a backward compatible break on a change. Specifically:
     structurally or by documentation.
 
 An exception to the above policy exists for:
-* Changes made within 14 days of the introduction of a new API field or message.
+* Changes made within 14 days of the introduction of a new API field or message, provided the new field
+or message has not been included in an Envoy release.
 * API versions tagged `vNalpha`. Within an alpha major version, arbitrary breaking changes are allowed.
 * Any field, message or enum with a `[#not-implemented-hide:..` comment.
 * Any proto with a `(udpa.annotations.file_status).work_in_progress` option annotation.