diff --git a/model/metric.go b/model/metric.go
index 49e3140aec..0cdae9262c 100644
--- a/model/metric.go
+++ b/model/metric.go
@@ -109,7 +109,7 @@ func (v Values) InsideInterval(t time.Time) (s bool) {
 		return
 	}
 
-	if t.Before(v[0]).Timestamp {
+	if t.Before(v[0].Timestamp) {
 		return
 	}