diff --git a/components/engine/runtime/container.go b/components/engine/runtime/container.go
index a9b81819d6..a2b75d2394 100644
--- a/components/engine/runtime/container.go
+++ b/components/engine/runtime/container.go
@@ -112,10 +112,6 @@ func (container *Container) Inject(file io.Reader, pth string) error {
 	return nil
 }
 
-func (container *Container) When() time.Time {
-	return container.Created
-}
-
 func (container *Container) FromDisk() error {
 	data, err := ioutil.ReadFile(container.jsonPath())
 	if err != nil {
diff --git a/components/engine/runtime/history.go b/components/engine/runtime/history.go
index 835ac9c11e..bce3d7005a 100644
--- a/components/engine/runtime/history.go
+++ b/components/engine/runtime/history.go
@@ -14,7 +14,7 @@ func (history *History) Len() int {
 
 func (history *History) Less(i, j int) bool {
 	containers := *history
-	return containers[j].When().Before(containers[i].When())
+	return containers[j].Created.Before(containers[i].Created)
 }
 
 func (history *History) Swap(i, j int) {