diff --git a/arshal_test.go b/arshal_test.go
index 909e060..cb1c140 100644
--- a/arshal_test.go
+++ b/arshal_test.go
@@ -132,9 +132,9 @@ type (
 		// cannot be called on an unexported field.
 		netipAddr `json:"name"`
 
-		// structMethodText has a MarshalText method
-		// that cancels out netipAddr.MarshalText.
-		structMethodText
+		// Bogus MarshalText and AppendText methods are declared on
+		// structUnexportedEmbeddedMethodTag to prevent it from
+		// implementing those method interfaces.
 	}
 	structUnexportedEmbeddedStruct struct {
 		structOmitZeroAll
@@ -573,6 +573,9 @@ type (
 	}
 )
 
+func (structUnexportedEmbeddedMethodTag) MarshalText() {}
+func (structUnexportedEmbeddedMethodTag) AppendText()  {}
+
 func (p *allMethods) MarshalJSONV2(enc *jsontext.Encoder, opts Options) error {
 	if got, want := "MarshalJSONV2", p.method; got != want {
 		return fmt.Errorf("called wrong method: got %v, want %v", got, want)
@@ -9223,7 +9226,9 @@ func TestCoderBufferGrowth(t *testing.T) {
 		}
 	}
 
-	bb := &bytesBuffer{new(bytes.Buffer)}
+	// bb is identical to bytes.Buffer,
+	// but a different type to avoid any optimizations for bytes.Buffer.
+	bb := struct{ *bytes.Buffer }{new(bytes.Buffer)}
 
 	var writeSizes []int
 	if err := MarshalWrite(WriterFunc(func(b []byte) (int, error) {
diff --git a/bench_test.go b/bench_test.go
index f209dfb..8bc94b7 100644
--- a/bench_test.go
+++ b/bench_test.go
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-package json
+package json_test
 
 import (
 	"bytes"
@@ -18,6 +18,7 @@ import (
 
 	jsonv1 "encoding/json"
 
+	jsonv2 "github.com/go-json-experiment/json"
 	"github.com/go-json-experiment/json/internal/jsontest"
 	"github.com/go-json-experiment/json/jsontext"
 )
@@ -28,6 +29,14 @@ var benchV1 = os.Getenv("BENCHMARK_V1") != ""
 // but a different type to avoid any optimizations for bytes.Buffer.
 type bytesBuffer struct{ *bytes.Buffer }
 
+func addr[T any](v T) *T {
+	return &v
+}
+
+func len64[Bytes ~[]byte | ~string](in Bytes) int64 {
+	return int64(len(in))
+}
+
 var arshalTestdata = []struct {
 	name   string
 	raw    []byte
@@ -206,10 +215,10 @@ func (*jsonArshalerV1) UnmarshalJSON(b []byte) error {
 
 type jsonArshalerV2 struct{ _ [4]int }
 
-func (jsonArshalerV2) MarshalJSONV2(enc *jsontext.Encoder, opts Options) error {
+func (jsonArshalerV2) MarshalJSONV2(enc *jsontext.Encoder, opts jsonv2.Options) error {
 	return enc.WriteToken(jsontext.String("method"))
 }
-func (*jsonArshalerV2) UnmarshalJSONV2(dec *jsontext.Decoder, opts Options) error {
+func (*jsonArshalerV2) UnmarshalJSONV2(dec *jsontext.Decoder, opts jsonv2.Options) error {
 	b, err := dec.ReadValue()
 	if string(b) != `"method"` {
 		return fmt.Errorf("UnmarshalJSONV2: got %q, want %q", b, `"method"`)
@@ -226,7 +235,7 @@ func runUnmarshal(tb testing.TB) {
 		var val any
 		run := func(tb testing.TB) {
 			val = tt.new()
-			if err := Unmarshal(tt.raw, val); err != nil {
+			if err := jsonv2.Unmarshal(tt.raw, val); err != nil {
 				tb.Fatalf("Unmarshal error: %v", err)
 			}
 		}
@@ -266,7 +275,7 @@ func runMarshal(tb testing.TB) {
 		var raw []byte
 		run := func(tb testing.TB) {
 			var err error
-			raw, err = Marshal(tt.val)
+			raw, err = jsonv2.Marshal(tt.val)
 			if err != nil {
 				tb.Fatalf("Marshal error: %v", err)
 			}
@@ -347,7 +356,7 @@ func runAllTestdata(tb testing.TB) {
 
 func mustUnmarshalValue(t testing.TB, data []byte, newValue func() any) (value any) {
 	value = newValue()
-	if err := Unmarshal(data, value); err != nil {
+	if err := jsonv2.Unmarshal(data, value); err != nil {
 		t.Fatalf("Unmarshal error: %v", err)
 	}
 	return value
@@ -370,11 +379,11 @@ func runArshal(t testing.TB, arshalName string, newValue func() any, data []byte
 
 	switch arshalName {
 	case "Marshal":
-		if _, err := Marshal(value); err != nil {
+		if _, err := jsonv2.Marshal(value); err != nil {
 			t.Fatalf("Marshal error: %v", err)
 		}
 	case "Unmarshal":
-		if err := Unmarshal(data, newValue()); err != nil {
+		if err := jsonv2.Unmarshal(data, newValue()); err != nil {
 			t.Fatalf("Unmarshal error: %v", err)
 		}
 	}
diff --git a/fold_test.go b/fold_test.go
index 1be7c13..fc7e421 100644
--- a/fold_test.go
+++ b/fold_test.go
@@ -9,8 +9,6 @@ import (
 	"reflect"
 	"testing"
 	"unicode"
-
-	jsonv1 "encoding/json"
 )
 
 var equalFoldTestdata = []struct {
@@ -103,18 +101,10 @@ func TestFoldRune(t *testing.T) {
 // TestBenchmarkUnmarshalUnknown unmarshals an unknown field into a struct with
 // varying number of fields. Since the unknown field does not directly match
 // any known field by name, it must fall back on case-insensitive matching.
-func TestBenchmarkUnmarshalUnknown(t *testing.T) { runUnmarshalUnknown(t) }
-func BenchmarkUnmarshalUnknown(b *testing.B)     { runUnmarshalUnknown(b) }
-
-func runUnmarshalUnknown(tb testing.TB) {
+func TestBenchmarkUnmarshalUnknown(t *testing.T) {
 	in := []byte(`{"NameUnknown":null}`)
 	for _, n := range []int{1, 2, 5, 10, 20, 50, 100} {
 		unmarshal := Unmarshal
-		if benchV1 {
-			unmarshal = func(in []byte, out any, opts ...Options) error {
-				return jsonv1.Unmarshal(in, out)
-			}
-		}
 
 		var fields []reflect.StructField
 		for i := range n {
@@ -126,9 +116,9 @@ func runUnmarshalUnknown(tb testing.TB) {
 		}
 		out := reflect.New(reflect.StructOf(fields)).Interface()
 
-		runTestOrBench(tb, fmt.Sprintf("N%d", n), len64(in), func(tb testing.TB) {
+		t.Run(fmt.Sprintf("N%d", n), func(t *testing.T) {
 			if err := unmarshal(in, out); err != nil {
-				tb.Fatalf("Unmarshal error: %v", err)
+				t.Fatalf("Unmarshal error: %v", err)
 			}
 		})
 	}