diff --git a/internal/restic/duration.go b/internal/restic/duration.go
index ed5acf24e..f10d1e811 100644
--- a/internal/restic/duration.go
+++ b/internal/restic/duration.go
@@ -127,7 +127,7 @@ func (d *Duration) Set(s string) error {
 	return nil
 }
 
-// Subtract duration from t to return past point in time.  If t is not given, use time.Now().
+// ParseTime returns past point in time where this duration is relative to time t.  If t is not given, use time.Now().
 func (d Duration) PastTime(t ...time.Time) time.Time {
 	var reftime time.Time
 	if t == nil {