diff --git a/audio/mp3/decode_js.go b/audio/mp3/decode_js.go
index c92d5e85e..bc33edbec 100644
--- a/audio/mp3/decode_js.go
+++ b/audio/mp3/decode_js.go
@@ -172,6 +172,14 @@ func init() {
 	}
 }
 
+func float32ArrayToSlice(arr js.Value) []float32 {
+	f := make([]float32, arr.Length())
+	a := js.TypedArrayOf(f)
+	a.Call("set", arr)
+	a.Release()
+	return f
+}
+
 func decode(context *audio.Context, buf []byte, try int) (*Stream, error) {
 	if offlineAudioContextClass == js.Null() {
 		return nil, errors.New("audio/mp3: OfflineAudioContext is not available")
@@ -187,7 +195,7 @@ func decode(context *audio.Context, buf []byte, try int) (*Stream, error) {
 	// TODO: 1 is a correct second argument?
 	oc := offlineAudioContextClass.New(2, 1, context.SampleRate())
 
-	u8 := js.ValueOf(buf)
+	u8 := js.TypedArrayOf(buf)
 	a := u8.Get("buffer").Call("slice", u8.Get("byteOffset"), u8.Get("byteOffset").Int()+u8.Get("byteLength").Int())
 
 	oc.Call("decodeAudioData", a, js.NewCallback(func(args []js.Value) {
@@ -213,6 +221,7 @@ func decode(context *audio.Context, buf []byte, try int) (*Stream, error) {
 			ch <- errTryAgain
 		}
 	}))
+	u8.Release()
 
 	timeout := time.Duration(math.Pow(2, float64(try))) * time.Second
 
diff --git a/audio/mp3/float32_notwasm.go b/audio/mp3/float32_notwasm.go
deleted file mode 100644
index 3ebdfa713..000000000
--- a/audio/mp3/float32_notwasm.go
+++ /dev/null
@@ -1,26 +0,0 @@
-// Copyright 2018 The Ebiten 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.
-
-// +build js,!wasm
-
-package mp3
-
-import (
-	gjs "github.com/gopherjs/gopherjs/js"
-	"github.com/gopherjs/gopherwasm/js"
-)
-
-func float32ArrayToSlice(arr js.Value) []float32 {
-	return js.GetInternalObject(arr).(*gjs.Object).Interface().([]float32)
-}
diff --git a/audio/mp3/float32_wasm.go b/audio/mp3/float32_wasm.go
deleted file mode 100644
index d05d523f7..000000000
--- a/audio/mp3/float32_wasm.go
+++ /dev/null
@@ -1,38 +0,0 @@
-// Copyright 2018 The Ebiten 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.
-
-// +build js,wasm
-
-package mp3
-
-import (
-	"reflect"
-	"syscall/js"
-	"unsafe"
-)
-
-func float32ArrayToSlice(arr js.Value) []float32 {
-	bytes := make([]byte, arr.Length()*4)
-	buf := arr.Get("buffer").Call("slice", arr.Get("byteOffset"), arr.Get("byteOffset").Int()+arr.Get("byteLength").Int())
-	js.ValueOf(bytes).Call("set", js.Global().Get("Uint8Array").New(buf))
-
-	bh := (*reflect.SliceHeader)(unsafe.Pointer(&bytes))
-	var f []float32
-	fh := (*reflect.SliceHeader)(unsafe.Pointer(&f))
-
-	fh.Data = bh.Data
-	fh.Len = bh.Len / 4
-	fh.Cap = bh.Cap / 4
-	return f
-}