diff --git a/components/script/dom/audiobuffer.rs b/components/script/dom/audiobuffer.rs
index 5d028cc3cd9..f732d39ea63 100644
--- a/components/script/dom/audiobuffer.rs
+++ b/components/script/dom/audiobuffer.rs
@@ -16,7 +16,6 @@ use js::rust::CustomAutoRooterGuard;
 use js::typedarray::{CreateWith, Float32Array};
 use servo_media::audio::buffer_source_node::AudioBuffer as ServoMediaAudioBuffer;
 use std::ptr::{self, NonNull};
-use std::sync::{Arc, Mutex};
 
 type JSAudioChannel = Heap<*mut JSObject>;
 
@@ -24,8 +23,8 @@ type JSAudioChannel = Heap<*mut JSObject>;
 pub struct AudioBuffer {
     reflector_: Reflector,
     js_channels: DomRefCell<Vec<JSAudioChannel>>,
-    #[ignore_malloc_size_of = "Arc"]
-    shared_channels: Arc<Mutex<ServoMediaAudioBuffer>>,
+    #[ignore_malloc_size_of = "servo_media"]
+    shared_channels: DomRefCell<ServoMediaAudioBuffer>,
     sample_rate: f32,
     length: u32,
     duration: f64,
@@ -53,12 +52,11 @@ impl AudioBuffer {
         AudioBuffer {
             reflector_: Reflector::new(),
             js_channels: DomRefCell::new(js_channels),
-            shared_channels: Arc::new(Mutex::new(
-                    ServoMediaAudioBuffer::new(number_of_channels as u8, length as usize))),
-                    sample_rate: sample_rate,
-                    length: length,
-                    duration: length as f64 / sample_rate as f64,
-                    number_of_channels: number_of_channels,
+            shared_channels: DomRefCell::new(ServoMediaAudioBuffer::new(number_of_channels as u8, length as usize)),
+            sample_rate,
+            length,
+            duration: length as f64 / sample_rate as f64,
+            number_of_channels,
         }
     }
 
@@ -89,7 +87,7 @@ impl AudioBuffer {
 
             // Move the channel data from shared_channels to js_channels.
             rooted!(in (cx) let mut array = ptr::null_mut::<JSObject>());
-            let shared_channel = (*self.shared_channels.lock().unwrap()).buffers.remove(i);
+            let shared_channel = (*self.shared_channels.borrow_mut()).buffers.remove(i);
             if unsafe {
                 Float32Array::create(cx, CreateWith::Slice(&shared_channel), array.handle_mut())
             }.is_err() {
@@ -103,7 +101,7 @@ impl AudioBuffer {
 
     /// https://webaudio.github.io/web-audio-api/#acquire-the-content
     #[allow(unsafe_code)]
-    pub fn acquire_contents(&self) -> Option<Arc<Mutex<ServoMediaAudioBuffer>>> {
+    pub fn acquire_contents(&self) -> Option<ServoMediaAudioBuffer> {
         let cx = self.global().get_cx();
         for (i, channel) in self.js_channels.borrow_mut().iter().enumerate() {
             // Step 1.
@@ -128,7 +126,7 @@ impl AudioBuffer {
             channel.set(ptr::null_mut());
 
             // Step 3.
-            (*self.shared_channels.lock().unwrap()).buffers[i] = channel_data;
+            (*self.shared_channels.borrow_mut()).buffers[i] = channel_data;
 
             // Step 4 will complete turning shared_channels
             // data into js_channels ArrayBuffers in restore_js_channel_data.
@@ -136,7 +134,7 @@ impl AudioBuffer {
 
         self.js_channels.borrow_mut().clear();
 
-        Some(self.shared_channels.clone())
+        Some((*self.shared_channels.borrow()).clone())
     }
 }