diff --git a/app/vmselect/promql/transform.go b/app/vmselect/promql/transform.go
index 3ce79d016..0088e3044 100644
--- a/app/vmselect/promql/transform.go
+++ b/app/vmselect/promql/transform.go
@@ -2743,14 +2743,15 @@ func copyTimeseriesMetricNames(tss []*timeseries, makeCopy bool) []*timeseries {
 	return rvs
 }
 
-// copyTimeseriesShallow returns a copy of arg with shallow copies of MetricNames,
-// Timestamps and Values.
-func copyTimeseriesShallow(arg []*timeseries) []*timeseries {
-	rvs := make([]*timeseries, len(arg))
-	for i, src := range arg {
-		var dst timeseries
-		dst.CopyShallow(src)
-		rvs[i] = &dst
+// copyTimeseriesShallow returns a copy of src with shallow copies of MetricNames, Timestamps and Values.
+func copyTimeseriesShallow(src []*timeseries) []*timeseries {
+	tss := make([]timeseries, len(src))
+	for i, src := range src {
+		tss[i].CopyShallow(src)
+	}
+	rvs := make([]*timeseries, len(tss))
+	for i := range tss {
+		rvs[i] = &tss[i]
 	}
 	return rvs
 }