diff --git a/util/time/duration.go b/util/time/duration.go
index fa431d92..ae2b716f 100644
--- a/util/time/duration.go
+++ b/util/time/duration.go
@@ -78,5 +78,5 @@ func (d Duration) MarshalYAML() (interface{}, error) {
 	return nil, nil
 }
 
-func (d Duration)
+func (d Duration) UnmarshalYAML(fn func(interface{}) error) error
 */