diff --git a/rules/alerting.go b/rules/alerting.go
index e8313d6f99..1e765665c0 100644
--- a/rules/alerting.go
+++ b/rules/alerting.go
@@ -24,7 +24,6 @@ import (
 
 	"github.com/prometheus/prometheus/pkg/strutil"
 	"github.com/prometheus/prometheus/promql"
-	"github.com/prometheus/prometheus/utility"
 )
 
 const (
@@ -149,10 +148,10 @@ func (rule *AlertingRule) Eval(timestamp clientmodel.Timestamp, engine *promql.E
 
 	// Create pending alerts for any new vector elements in the alert expression
 	// or update the expression value for existing elements.
-	resultFingerprints := utility.Set{}
+	resultFPs := map[clientmodel.Fingerprint]struct{}{}
 	for _, sample := range exprResult {
 		fp := sample.Metric.Metric.Fingerprint()
-		resultFingerprints.Add(fp)
+		resultFPs[fp] = struct{}{}
 
 		if alert, ok := rule.activeAlerts[fp]; !ok {
 			labels := clientmodel.LabelSet{}
@@ -177,7 +176,7 @@ func (rule *AlertingRule) Eval(timestamp clientmodel.Timestamp, engine *promql.E
 
 	// Check if any pending alerts should be removed or fire now. Write out alert timeseries.
 	for fp, activeAlert := range rule.activeAlerts {
-		if !resultFingerprints.Has(fp) {
+		if _, ok := resultFPs[fp]; !ok {
 			vector = append(vector, activeAlert.sample(timestamp, 0))
 			delete(rule.activeAlerts, fp)
 			continue
diff --git a/utility/set.go b/utility/set.go
deleted file mode 100644
index ba1034e3ae..0000000000
--- a/utility/set.go
+++ /dev/null
@@ -1,58 +0,0 @@
-// Copyright 2013 The Prometheus Authors
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-// http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-package utility
-
-// Set is a type which models a set.
-type Set map[interface{}]struct{}
-
-// Add adds an item to the set.
-func (s Set) Add(v interface{}) {
-	s[v] = struct{}{}
-}
-
-// Remove removes an item from the set.
-func (s Set) Remove(v interface{}) {
-	delete(s, v)
-}
-
-// Elements returns a slice containing all elements in the set.
-func (s Set) Elements() []interface{} {
-	result := make([]interface{}, 0, len(s))
-
-	for k := range s {
-		result = append(result, k)
-	}
-
-	return result
-}
-
-// Has returns true if an element is contained in the set.
-func (s Set) Has(v interface{}) bool {
-	_, p := s[v]
-
-	return p
-}
-
-// Intersection returns a new set with items that exist in both sets.
-func (s Set) Intersection(o Set) Set {
-	result := Set{}
-
-	for k := range s {
-		if o.Has(k) {
-			result[k] = struct{}{}
-		}
-	}
-
-	return result
-}
diff --git a/utility/set_test.go b/utility/set_test.go
deleted file mode 100644
index 7c2279845d..0000000000
--- a/utility/set_test.go
+++ /dev/null
@@ -1,122 +0,0 @@
-// Copyright 2013 The Prometheus Authors
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-// http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-package utility
-
-import (
-	"testing"
-	"testing/quick"
-)
-
-func TestSetEqualMemberships(t *testing.T) {
-	f := func(x int) bool {
-		first := make(Set)
-		second := make(Set)
-
-		first.Add(x)
-		second.Add(x)
-
-		intersection := first.Intersection(second)
-
-		members := intersection.Elements()
-
-		return members != nil && len(members) == 1 && members[0] == x
-	}
-
-	if err := quick.Check(f, nil); err != nil {
-		t.Error(err)
-	}
-}
-
-func TestSetInequalMemberships(t *testing.T) {
-	f := func(x int) bool {
-		first := make(Set)
-		second := make(Set)
-
-		first.Add(x)
-
-		intersection := first.Intersection(second)
-
-		members := intersection.Elements()
-
-		return members != nil && len(members) == 0
-	}
-
-	if err := quick.Check(f, nil); err != nil {
-		t.Error(err)
-	}
-}
-
-func TestSetAsymmetricMemberships(t *testing.T) {
-	f := func(x int) bool {
-		first := make(Set)
-		second := make(Set)
-
-		first.Add(x)
-		second.Add(x)
-		first.Add(x + 1)
-		second.Add(x + 1)
-		second.Add(x + 2)
-		first.Add(x + 2)
-		first.Add(x + 3)
-		second.Add(x + 4)
-
-		intersection := first.Intersection(second)
-
-		members := intersection.Elements()
-
-		return members != nil && len(members) == 3
-	}
-
-	if err := quick.Check(f, nil); err != nil {
-		t.Error(err)
-	}
-}
-
-func TestSetRemoval(t *testing.T) {
-	f := func(x int) bool {
-		first := make(Set)
-
-		first.Add(x)
-		first.Remove(x)
-
-		members := first.Elements()
-
-		return members != nil && len(members) == 0
-	}
-
-	if err := quick.Check(f, nil); err != nil {
-		t.Error(err)
-	}
-}
-
-func TestSetAdditionAndRemoval(t *testing.T) {
-	f := func(x int) bool {
-		first := make(Set)
-		second := make(Set)
-
-		first.Add(x)
-		second.Add(x)
-		first.Add(x + 1)
-		first.Remove(x + 1)
-
-		intersection := first.Intersection(second)
-		members := intersection.Elements()
-
-		return members != nil && len(members) == 1 && members[0] == x
-	}
-
-	if err := quick.Check(f, nil); err != nil {
-		t.Error(err)
-	}
-}