diff --git a/provisioner/storage.go b/provisioner/storage.go
index b12b7ef..2d2fb6d 100644
--- a/provisioner/storage.go
+++ b/provisioner/storage.go
@@ -9,6 +9,7 @@
 type Storage interface {
 	Put(id string, update StatusMsg) error
 	Get(id string) (*StatusMsg, error)
+	Delete(id string) error
 	List() ([]StatusMsg, error)
 }
 
@@ -51,6 +52,11 @@
 	return &m, nil
 }
 
+func (s *MemoryStorage) Delete(id string) error {
+	delete(s.Data, id)
+	return nil
+}
+
 func (s *MemoryStorage) List() ([]StatusMsg, error) {
 	r := make([]StatusMsg, len(s.Data))
 	i := 0