diff --git a/go.mod b/go.mod
index 99d0457..51311fc 100644
--- a/go.mod
+++ b/go.mod
@@ -2,6 +2,7 @@ module github.com/prometheus/client_golang
 
 require (
 	github.com/beorn7/perks v1.0.1
+	github.com/cespare/xxhash/v2 v2.1.0
 	github.com/golang/protobuf v1.3.2
 	github.com/json-iterator/go v1.1.7
 	github.com/prometheus/client_model v0.0.0-20190812154241-14fe0d1b01d4
diff --git a/go.sum b/go.sum
index 5f52411..a0e4eff 100644
--- a/go.sum
+++ b/go.sum
@@ -8,6 +8,8 @@ github.com/beorn7/perks v1.0.0 h1:HWo1m869IqiPhD389kmkxeTalrjNbbJTC8LXupb+sl0=
 github.com/beorn7/perks v1.0.0/go.mod h1:KWe93zE9D1o94FZ5RNwFwVgaQK1VOXiVxmqh+CedLV8=
 github.com/beorn7/perks v1.0.1 h1:VlbKKnNfV8bJzeqoa4cOKqO6bYr3WgKZxO8Z16+hsOM=
 github.com/beorn7/perks v1.0.1/go.mod h1:G2ZrVWU2WbWT9wwq4/hrbKbnv/1ERSJQ0ibhJ6rlkpw=
+github.com/cespare/xxhash/v2 v2.1.0 h1:yTUvW7Vhb89inJ+8irsUqiWjh8iT6sQPZiQzI6ReGkA=
+github.com/cespare/xxhash/v2 v2.1.0/go.mod h1:dgIUBU3pDso/gPgZ1osOZ0iQf77oPR28Tjxl5dIMyVM=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
diff --git a/prometheus/desc.go b/prometheus/desc.go
index 1d034f8..e3232d7 100644
--- a/prometheus/desc.go
+++ b/prometheus/desc.go
@@ -19,6 +19,7 @@ import (
 	"sort"
 	"strings"
 
+	"github.com/cespare/xxhash/v2"
 	"github.com/golang/protobuf/proto"
 	"github.com/prometheus/common/model"
 
@@ -126,24 +127,24 @@ func NewDesc(fqName, help string, variableLabels []string, constLabels Labels) *
 		return d
 	}
 
-	vh := hashNew()
+	xxh := xxhash.New()
 	for _, val := range labelValues {
-		vh = hashAdd(vh, val)
-		vh = hashAddByte(vh, separatorByte)
+		xxh.WriteString(val)
+		xxh.Write(separatorByteSlice)
 	}
-	d.id = vh
+	d.id = xxh.Sum64()
 	// Sort labelNames so that order doesn't matter for the hash.
 	sort.Strings(labelNames)
 	// Now hash together (in this order) the help string and the sorted
 	// label names.
-	lh := hashNew()
-	lh = hashAdd(lh, help)
-	lh = hashAddByte(lh, separatorByte)
+	xxh.Reset()
+	xxh.WriteString(help)
+	xxh.Write(separatorByteSlice)
 	for _, labelName := range labelNames {
-		lh = hashAdd(lh, labelName)
-		lh = hashAddByte(lh, separatorByte)
+		xxh.WriteString(labelName)
+		xxh.Write(separatorByteSlice)
 	}
-	d.dimHash = lh
+	d.dimHash = xxh.Sum64()
 
 	d.constLabelPairs = make([]*dto.LabelPair, 0, len(constLabels))
 	for n, v := range constLabels {
diff --git a/prometheus/metric.go b/prometheus/metric.go
index 55e6d86..5bb7f80 100644
--- a/prometheus/metric.go
+++ b/prometheus/metric.go
@@ -24,6 +24,8 @@ import (
 
 const separatorByte byte = 255
 
+var separatorByteSlice = []byte{255} // For convenient use with xxhash.
+
 // A Metric models a single sample value with its meta data being exported to
 // Prometheus. Implementations of Metric in this package are Gauge, Counter,
 // Histogram, Summary, and Untyped.
diff --git a/prometheus/registry.go b/prometheus/registry.go
index 1edcf2f..b1f8ed8 100644
--- a/prometheus/registry.go
+++ b/prometheus/registry.go
@@ -25,6 +25,7 @@ import (
 	"sync"
 	"unicode/utf8"
 
+	"github.com/cespare/xxhash/v2"
 	"github.com/golang/protobuf/proto"
 	"github.com/prometheus/common/expfmt"
 
@@ -875,9 +876,9 @@ func checkMetricConsistency(
 	}
 
 	// Is the metric unique (i.e. no other metric with the same name and the same labels)?
-	h := hashNew()
-	h = hashAdd(h, name)
-	h = hashAddByte(h, separatorByte)
+	h := xxhash.New()
+	h.WriteString(name)
+	h.Write(separatorByteSlice)
 	// Make sure label pairs are sorted. We depend on it for the consistency
 	// check.
 	if !sort.IsSorted(labelPairSorter(dtoMetric.Label)) {
@@ -888,18 +889,19 @@ func checkMetricConsistency(
 		dtoMetric.Label = copiedLabels
 	}
 	for _, lp := range dtoMetric.Label {
-		h = hashAdd(h, lp.GetName())
-		h = hashAddByte(h, separatorByte)
-		h = hashAdd(h, lp.GetValue())
-		h = hashAddByte(h, separatorByte)
+		h.WriteString(lp.GetName())
+		h.Write(separatorByteSlice)
+		h.WriteString(lp.GetValue())
+		h.Write(separatorByteSlice)
 	}
-	if _, exists := metricHashes[h]; exists {
+	hSum := h.Sum64()
+	if _, exists := metricHashes[hSum]; exists {
 		return fmt.Errorf(
 			"collected metric %q { %s} was collected before with the same name and label values",
 			name, dtoMetric,
 		)
 	}
-	metricHashes[h] = struct{}{}
+	metricHashes[hSum] = struct{}{}
 	return nil
 }