diff --git a/content/media/webaudio/AudioContext.cpp b/content/media/webaudio/AudioContext.cpp
index 825685f668a..5cb293f8ef7 100644
--- a/content/media/webaudio/AudioContext.cpp
+++ b/content/media/webaudio/AudioContext.cpp
@@ -430,22 +430,29 @@ AudioContext::DecodeAudioData(const ArrayBuffer& aBuffer,
                               DecodeSuccessCallback& aSuccessCallback,
                               const Optional<OwningNonNull<DecodeErrorCallback> >& aFailureCallback)
 {
+  AutoJSAPI jsapi;
+  JSContext* cx = jsapi.cx();
+  JSAutoCompartment ac(cx, aBuffer.Obj());
+
+  // Neuter the array buffer
+  size_t length = aBuffer.Length();
+  JS::RootedObject obj(cx, aBuffer.Obj());
+
+  uint8_t* data = static_cast<uint8_t*>(JS_StealArrayBufferContents(cx, obj));
+
   // Sniff the content of the media.
   // Failed type sniffing will be handled by AsyncDecodeMedia.
   nsAutoCString contentType;
-  NS_SniffContent(NS_DATA_SNIFFER_CATEGORY, nullptr,
-                  aBuffer.Data(), aBuffer.Length(),
-                  contentType);
+  NS_SniffContent(NS_DATA_SNIFFER_CATEGORY, nullptr, data, length, contentType);
 
   nsRefPtr<DecodeErrorCallback> failureCallback;
   if (aFailureCallback.WasPassed()) {
     failureCallback = &aFailureCallback.Value();
   }
   nsRefPtr<WebAudioDecodeJob> job(
-    new WebAudioDecodeJob(contentType, this, aBuffer,
+    new WebAudioDecodeJob(contentType, this,
                           &aSuccessCallback, failureCallback));
-  mDecoder.AsyncDecodeMedia(contentType.get(),
-                            aBuffer.Data(), aBuffer.Length(), *job);
+  mDecoder.AsyncDecodeMedia(contentType.get(), data, length, *job);
   // Transfer the ownership to mDecodeJobs
   mDecodeJobs.AppendElement(job);
 }
diff --git a/content/media/webaudio/MediaBufferDecoder.cpp b/content/media/webaudio/MediaBufferDecoder.cpp
index a113b110c24..5172b18a474 100644
--- a/content/media/webaudio/MediaBufferDecoder.cpp
+++ b/content/media/webaudio/MediaBufferDecoder.cpp
@@ -30,7 +30,6 @@ NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN(WebAudioDecodeJob)
   NS_IMPL_CYCLE_COLLECTION_UNLINK(mOutput)
   NS_IMPL_CYCLE_COLLECTION_UNLINK(mSuccessCallback)
   NS_IMPL_CYCLE_COLLECTION_UNLINK(mFailureCallback)
-  tmp->mArrayBuffer = nullptr;
 NS_IMPL_CYCLE_COLLECTION_UNLINK_END
 
 NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN(WebAudioDecodeJob)
@@ -42,9 +41,7 @@ NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN(WebAudioDecodeJob)
 NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
 
 NS_IMPL_CYCLE_COLLECTION_TRACE_BEGIN(WebAudioDecodeJob)
-  NS_IMPL_CYCLE_COLLECTION_TRACE_JS_MEMBER_CALLBACK(mArrayBuffer)
 NS_IMPL_CYCLE_COLLECTION_TRACE_END
-
 NS_IMPL_CYCLE_COLLECTION_ROOT_NATIVE(WebAudioDecodeJob, AddRef)
 NS_IMPL_CYCLE_COLLECTION_UNROOT_NATIVE(WebAudioDecodeJob, Release)
 
@@ -143,6 +140,7 @@ private:
     // Destruct MediaDecoderReader first.
     mDecoderReader = nullptr;
     mBufferDecoder = nullptr;
+    JS_free(nullptr, mBuffer);
   }
 
 private:
@@ -482,7 +480,6 @@ MediaBufferDecoder::EnsureThreadPoolInitialized()
 
 WebAudioDecodeJob::WebAudioDecodeJob(const nsACString& aContentType,
                                      AudioContext* aContext,
-                                     const ArrayBuffer& aBuffer,
                                      DecodeSuccessCallback* aSuccessCallback,
                                      DecodeErrorCallback* aFailureCallback)
   : mContentType(aContentType)
@@ -495,18 +492,12 @@ WebAudioDecodeJob::WebAudioDecodeJob(const nsACString& aContentType,
   MOZ_ASSERT(aSuccessCallback);
   MOZ_ASSERT(NS_IsMainThread());
   MOZ_COUNT_CTOR(WebAudioDecodeJob);
-
-  mArrayBuffer = aBuffer.Obj();
-
-  mozilla::HoldJSObjects(this);
 }
 
 WebAudioDecodeJob::~WebAudioDecodeJob()
 {
   MOZ_ASSERT(NS_IsMainThread());
   MOZ_COUNT_DTOR(WebAudioDecodeJob);
-  mArrayBuffer = nullptr;
-  mozilla::DropJSObjects(this);
 }
 
 void
diff --git a/content/media/webaudio/MediaBufferDecoder.h b/content/media/webaudio/MediaBufferDecoder.h
index 38f867cc82b..f04ab3fc7cc 100644
--- a/content/media/webaudio/MediaBufferDecoder.h
+++ b/content/media/webaudio/MediaBufferDecoder.h
@@ -32,7 +32,6 @@ struct WebAudioDecodeJob MOZ_FINAL
   // The callbacks are only necessary for asynchronous operation.
   WebAudioDecodeJob(const nsACString& aContentType,
                     dom::AudioContext* aContext,
-                    const dom::ArrayBuffer& aBuffer,
                     dom::DecodeSuccessCallback* aSuccessCallback = nullptr,
                     dom::DecodeErrorCallback* aFailureCallback = nullptr);
   ~WebAudioDecodeJob();
@@ -59,7 +58,6 @@ struct WebAudioDecodeJob MOZ_FINAL
   size_t SizeOfExcludingThis(mozilla::MallocSizeOf aMallocSizeOf) const;
   size_t SizeOfIncludingThis(mozilla::MallocSizeOf aMallocSizeOf) const;
 
-  JS::Heap<JSObject*> mArrayBuffer;
   nsCString mContentType;
   uint32_t mWriteIndex;
   nsRefPtr<dom::AudioContext> mContext;
diff --git a/content/media/webaudio/test/test_mediaDecoding.html b/content/media/webaudio/test/test_mediaDecoding.html
index 8d7f49d97ae..9a32d105031 100644
--- a/content/media/webaudio/test/test_mediaDecoding.html
+++ b/content/media/webaudio/test/test_mediaDecoding.html
@@ -311,6 +311,9 @@ function runResampling(test, response, callback) {
 }
 
 function runTest(test, response, callback) {
+  // We need to copy the array here, because decodeAudioData is going to neuter
+  // the array.
+  var compressedAudio = response.slice(0);
   var expectCallback = false;
   var cx = new OfflineAudioContext(test.numberOfChannels || 1,
                                    test.frames || 1, test.sampleRate);
@@ -322,7 +325,7 @@ function runTest(test, response, callback) {
 
     test.expectedBuffer = asyncResult;
     test.nativeContext = cx;
-    runResampling(test, response, callback);
+    runResampling(test, compressedAudio, callback);
   }, function onFailure() {
     ok(expectCallback, "Failure callback should fire asynchronously");
     ok(!test.valid, "Did expect failure for test " + test.url);