diff --git a/src/encoding/asn1/asn1.go b/src/encoding/asn1/asn1.go
index f743cd6f69..e7bf793a82 100644
--- a/src/encoding/asn1/asn1.go
+++ b/src/encoding/asn1/asn1.go
@@ -26,6 +26,7 @@ import (
 	"math/big"
 	"reflect"
 	"strconv"
+	"strings"
 	"time"
 	"unicode/utf16"
 	"unicode/utf8"
@@ -236,16 +237,18 @@ func (oi ObjectIdentifier) Equal(other ObjectIdentifier) bool {
 }
 
 func (oi ObjectIdentifier) String() string {
-	var s string
+	var s strings.Builder
+	s.Grow(32)
 
+	buf := make([]byte, 0, 19)
 	for i, v := range oi {
 		if i > 0 {
-			s += "."
+			s.WriteByte('.')
 		}
-		s += strconv.Itoa(v)
+		s.Write(strconv.AppendInt(buf, int64(v), 10))
 	}
 
-	return s
+	return s.String()
 }
 
 // parseObjectIdentifier parses an OBJECT IDENTIFIER from the given bytes and
diff --git a/src/encoding/asn1/asn1_test.go b/src/encoding/asn1/asn1_test.go
index 0e67dbf396..9a605e245c 100644
--- a/src/encoding/asn1/asn1_test.go
+++ b/src/encoding/asn1/asn1_test.go
@@ -1168,3 +1168,10 @@ func TestNonMinimalEncodedOID(t *testing.T) {
 		t.Fatalf("accepted non-minimally encoded oid")
 	}
 }
+
+func BenchmarkObjectIdentifierString(b *testing.B) {
+	oidPublicKeyRSA := ObjectIdentifier{1, 2, 840, 113549, 1, 1, 1}
+	for i := 0; i < b.N; i++ {
+		_ = oidPublicKeyRSA.String()
+	}
+}