diff --git a/bandwidth.go b/bandwidth.go
index 15e0083..c0792f1 100644
--- a/bandwidth.go
+++ b/bandwidth.go
@@ -128,8 +128,9 @@ func (s *stream) averages() []float64 {
 	if s.data.Back() == nil {
 		return totals
 	}
-	newest := s.data.Back().Value.(datum)
-	cutoff := newest.at.Add(s.max)
+
+	now := time.Now()
+	cutoff := now.Add(s.max)
 	for e := s.data.Front(); e != nil; e = e.Next() {
 		cur := e.Value.(datum).at
 		if cur.Before(cutoff) {
@@ -142,7 +143,7 @@ func (s *stream) averages() []float64 {
 	e := s.data.Back()
 
 	for _, extent := range s.extents {
-		limit = newest.at.Add(extent)
+		limit = now.Add(extent)
 		for ; e != nil; e = e.Prev() {
 			if e.Prev() == nil {
 				break