diff --git a/promql/engine.go b/promql/engine.go
index e9985cec59..7a404dd333 100644
--- a/promql/engine.go
+++ b/promql/engine.go
@@ -431,7 +431,7 @@ func (ng *Engine) populateIterators(ctx context.Context, s *EvalStmt) (storage.Q
 
 func expandSeriesSet(it storage.SeriesSet) (res []storage.Series, err error) {
 	for it.Next() {
-		res = append(res, it.Series())
+		res = append(res, it.At())
 	}
 	return res, it.Err()
 }
@@ -676,7 +676,7 @@ func (ev *evaluator) matrixSelector(node *MatrixSelector) Matrix {
 
 		buf := it.Buffer()
 		for buf.Next() {
-			t, v := buf.Values()
+			t, v := buf.At()
 			// Values in the buffer are guaranteed to be smaller than maxt.
 			if t >= mint {
 				ss.Points = append(ss.Points, Point{T: t, V: v})
diff --git a/storage/buffer.go b/storage/buffer.go
index 2b23058f39..3076354680 100644
--- a/storage/buffer.go
+++ b/storage/buffer.go
@@ -62,7 +62,7 @@ func (b *BufferedSeriesIterator) Seek(t int64) bool {
 // Next advances the iterator to the next element.
 func (b *BufferedSeriesIterator) Next() bool {
 	// Add current element to buffer before advancing.
-	b.buf.add(b.it.Values())
+	b.buf.add(b.it.At())
 
 	ok := b.it.Next()
 	if ok {
@@ -73,7 +73,7 @@ func (b *BufferedSeriesIterator) Next() bool {
 
 // Values returns the current element of the iterator.
 func (b *BufferedSeriesIterator) Values() (int64, float64) {
-	return b.it.Values()
+	return b.it.At()
 }
 
 // Err returns the last encountered error.
@@ -130,7 +130,7 @@ func (it *sampleRingIterator) Err() error {
 	return nil
 }
 
-func (it *sampleRingIterator) Values() (int64, float64) {
+func (it *sampleRingIterator) At() (int64, float64) {
 	return it.r.at(it.i)
 }
 
diff --git a/storage/buffer_test.go b/storage/buffer_test.go
index a719b60ed1..e433fb9fa6 100644
--- a/storage/buffer_test.go
+++ b/storage/buffer_test.go
@@ -77,7 +77,7 @@ func TestBufferedSeriesIterator(t *testing.T) {
 		var b []sample
 		bit := it.Buffer()
 		for bit.Next() {
-			t, v := bit.Values()
+			t, v := bit.At()
 			b = append(b, sample{t: t, v: v})
 		}
 		require.Equal(t, exp, b, "buffer mismatch")
@@ -153,7 +153,7 @@ func newListSeriesIterator(list []sample) *listSeriesIterator {
 	return &listSeriesIterator{list: list, idx: -1}
 }
 
-func (it *listSeriesIterator) Values() (int64, float64) {
+func (it *listSeriesIterator) At() (int64, float64) {
 	s := it.list[it.idx]
 	return s.t, s.v
 }
diff --git a/storage/interface.go b/storage/interface.go
index 98b47cbf84..1f6a782ec7 100644
--- a/storage/interface.go
+++ b/storage/interface.go
@@ -61,7 +61,7 @@ type Appender interface {
 // SeriesSet contains a set of series.
 type SeriesSet interface {
 	Next() bool
-	Series() Series
+	At() Series
 	Err() error
 }
 
@@ -79,8 +79,8 @@ type SeriesIterator interface {
 	// Seek advances the iterator forward to the value at or after
 	// the given timestamp.
 	Seek(t int64) bool
-	// Values returns the current timestamp/value pair.
-	Values() (t int64, v float64)
+	// At returns the current timestamp/value pair.
+	At() (t int64, v float64)
 	// Next advances the iterator by one.
 	Next() bool
 	// Err returns the current error.
diff --git a/storage/tsdb/tsdb.go b/storage/tsdb/tsdb.go
index e49b3c6ced..f537f7e7cd 100644
--- a/storage/tsdb/tsdb.go
+++ b/storage/tsdb/tsdb.go
@@ -58,9 +58,9 @@ type seriesSet struct {
 	set tsdb.SeriesSet
 }
 
-func (s seriesSet) Next() bool             { return s.set.Next() }
-func (s seriesSet) Err() error             { return s.set.Err() }
-func (s seriesSet) Series() storage.Series { return series{s: s.set.Series()} }
+func (s seriesSet) Next() bool         { return s.set.Next() }
+func (s seriesSet) Err() error         { return s.set.Err() }
+func (s seriesSet) At() storage.Series { return series{s: s.set.At()} }
 
 type series struct {
 	s tsdb.Series
@@ -76,6 +76,7 @@ type appender struct {
 func (a appender) Add(lset labels.Labels, t int64, v float64) error {
 	return a.a.Add(toTSDBLabels(lset), t, v)
 }
+
 func (a appender) Commit() error { return a.a.Commit() }
 
 func convertMatcher(m *labels.Matcher) tsdbLabels.Matcher {
diff --git a/web/api/v1/api.go b/web/api/v1/api.go
index 9a1bad1aac..de5610b4b5 100644
--- a/web/api/v1/api.go
+++ b/web/api/v1/api.go
@@ -309,7 +309,7 @@ func (api *API) series(r *http.Request) (interface{}, *apiError) {
 	for _, mset := range matcherSets {
 		series := q.Select(mset...)
 		for series.Next() {
-			metrics = append(metrics, series.Series().Labels())
+			metrics = append(metrics, series.At().Labels())
 		}
 		if series.Err() != nil {
 			return nil, &apiError{errorExec, series.Err()}
diff --git a/web/federate.go b/web/federate.go
index 5b0fba7a65..c6a463d1fb 100644
--- a/web/federate.go
+++ b/web/federate.go
@@ -77,7 +77,7 @@ func (h *Handler) federation(w http.ResponseWriter, req *http.Request) {
 	for _, mset := range matcherSets {
 		series := q.Select(mset...)
 		for series.Next() {
-			s := series.Series()
+			s := series.At()
 			// TODO(fabxc): allow fast path for most recent sample either
 			// in the storage itself or caching layer in Prometheus.
 			it := storage.NewBuffer(s.Iterator(), int64(promql.StalenessDelta/1e6))