diff --git a/app/vmselect/promql/aggr_incremental.go b/app/vmselect/promql/aggr_incremental.go
index 581b3a8f5..26f91ed0e 100644
--- a/app/vmselect/promql/aggr_incremental.go
+++ b/app/vmselect/promql/aggr_incremental.go
@@ -5,6 +5,7 @@ import (
 	"strings"
 	"sync"
 
+	"github.com/VictoriaMetrics/VictoriaMetrics/lib/bytesutil"
 	"github.com/VictoriaMetrics/metricsql"
 )
 
@@ -98,7 +99,8 @@ func (iafc *incrementalAggrFuncContext) updateTimeseries(tsOrig *timeseries, wor
 	removeGroupTags(&ts.MetricName, &iafc.ae.Modifier)
 	bb := bbPool.Get()
 	bb.B = marshalMetricNameSorted(bb.B[:0], &ts.MetricName)
-	iac := m[string(bb.B)]
+	k := bytesutil.InternBytes(bb.B)
+	iac := m[k]
 	if iac == nil {
 		if iafc.ae.Limit > 0 && len(m) >= iafc.ae.Limit {
 			// Skip this time series, since the limit on the number of output time series has been already reached.
@@ -117,7 +119,7 @@ func (iafc *incrementalAggrFuncContext) updateTimeseries(tsOrig *timeseries, wor
 			ts:     tsAggr,
 			values: make([]float64, len(ts.Values)),
 		}
-		m[string(bb.B)] = iac
+		m[k] = iac
 	}
 	bbPool.Put(bb)
 	iafc.callbacks.updateAggrFunc(iac, ts.Values)