diff --git a/CHANGELOG.md b/CHANGELOG.md
index 8ff7b04..640617d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,6 +4,8 @@ All notable changes to this project are documented below.
 The format is based on [keep a changelog](http://keepachangelog.com) and this project uses [semantic versioning](http://semver.org).
 
 ## [Unreleased]
+### Fixed
+- Add ErrGracePeriodExpired.
 
 ## [1.32.0] - 2024-06-09
 ### Added
diff --git a/runtime/runtime.go b/runtime/runtime.go
index 411f777..042a549 100644
--- a/runtime/runtime.go
+++ b/runtime/runtime.go
@@ -197,6 +197,8 @@ var (
 	ErrPartyRemove                   = errors.New("party could not remove")
 	ErrPartyRemoveSelf               = errors.New("party cannot remove self")
 
+	ErrGracePeriodExpired = errors.New("grace period expired")
+
 	ErrGroupNameInUse         = errors.New("group name in use")
 	ErrGroupPermissionDenied  = errors.New("group permission denied")
 	ErrGroupNoUpdateOps       = errors.New("no group updates")