diff --git a/chunk_store.go b/chunk_store.go
index 41eef9c41be5..4363696cf0df 100644
--- a/chunk_store.go
+++ b/chunk_store.go
@@ -424,11 +424,13 @@ func (c *store) lookupChunksByMetricName(ctx context.Context, userID string, fro
 	// Receive chunkSets from all matchers
 	var chunkIDs []string
 	var lastErr error
+	var initialized bool
 	for i := 0; i < len(matchers); i++ {
 		select {
 		case incoming := <-incomingChunkIDs:
-			if chunkIDs == nil {
+			if !initialized {
 				chunkIDs = incoming
+				initialized = true
 			} else {
 				chunkIDs = intersectStrings(chunkIDs, incoming)
 			}
diff --git a/chunk_store_test.go b/chunk_store_test.go
index f983f71f3077..24a49d30c7d7 100644
--- a/chunk_store_test.go
+++ b/chunk_store_test.go
@@ -177,6 +177,10 @@ func TestChunkStore_Get(t *testing.T) {
 			query:  `foo{toms="code", bar="baz"}`,
 			expect: []Chunk{fooChunk1},
 		},
+		{
+			query:  `foo{a="b", bar="baz"}`,
+			expect: nil,
+		},
 		{
 			query: `{__name__=~"foo"}`,
 			err:   "query must contain metric name",
diff --git a/series_store.go b/series_store.go
index a1e062f9770c..4792ca1ae2e0 100644
--- a/series_store.go
+++ b/series_store.go
@@ -305,12 +305,14 @@ func (c *seriesStore) lookupSeriesByMetricNameMatchers(ctx context.Context, from
 	var lastErr error
 	var cardinalityExceededErrors int
 	var cardinalityExceededError CardinalityExceededError
+	var initialized bool
 	for i := 0; i < len(matchers); i++ {
 		select {
 		case incoming := <-incomingIDs:
 			preIntersectionCount += len(incoming)
-			if ids == nil {
+			if !initialized {
 				ids = incoming
+				initialized = true
 			} else {
 				ids = intersectStrings(ids, incoming)
 			}