--- a/dom/media/mediasource/SourceBuffer.cpp
+++ b/dom/media/mediasource/SourceBuffer.cpp
@@ -67,26 +67,31 @@ private:
   nsRefPtr<LargeDataBuffer> mData;
   double mTimestampOffset;
   uint32_t mUpdateID;
 };
 
 class RangeRemovalRunnable : public nsRunnable {
 public:
   RangeRemovalRunnable(SourceBuffer* aSourceBuffer,
-                     double aStart,
-                     double aEnd)
+                       double aStart,
+                       double aEnd)
   : mSourceBuffer(aSourceBuffer)
   , mStart(aStart)
   , mEnd(aEnd)
   { }
 
   NS_IMETHOD Run() MOZ_OVERRIDE MOZ_FINAL {
 
+    if (!mSourceBuffer->mUpdating) {
+      // abort was called in between.
+      return NS_OK;
+    }
     mSourceBuffer->DoRangeRemoval(mStart, mEnd);
+    mSourceBuffer->StopUpdating();
 
     return NS_OK;
   }
 
 private:
   nsRefPtr<SourceBuffer> mSourceBuffer;
   double mStart;
   double mEnd;
@@ -255,44 +260,41 @@ SourceBuffer::Remove(double aStart, doub
   }
   if (mUpdating) {
     aRv.Throw(NS_ERROR_DOM_INVALID_STATE_ERR);
     return;
   }
   if (mMediaSource->ReadyState() == MediaSourceReadyState::Ended) {
     mMediaSource->SetReadyState(MediaSourceReadyState::Open);
   }
-  RangeRemoval(aStart, aEnd);
+
+  StartUpdating();
+  nsRefPtr<nsIRunnable> task = new RangeRemovalRunnable(this, aStart, aEnd);
+  NS_DispatchToMainThread(task);
 }
 
 void
 SourceBuffer::RangeRemoval(double aStart, double aEnd)
 {
   StartUpdating();
-
-  nsRefPtr<nsIRunnable> task = new RangeRemovalRunnable(this, aStart, aEnd);
+  DoRangeRemoval(aStart, aEnd);
+  nsRefPtr<nsIRunnable> task =
+    NS_NewRunnableMethod(this, &SourceBuffer::StopUpdating);
   NS_DispatchToMainThread(task);
 }
 
 void
 SourceBuffer::DoRangeRemoval(double aStart, double aEnd)
 {
-  MSE_DEBUG("SourceBuffer(%p)::DoRangeRemoval (updating:%d)",
-            this, mUpdating);
-  if (!mUpdating) {
-    // abort was called in between.
-    return;
-  }
+  MSE_DEBUG("SourceBuffer(%p)::DoRangeRemoval", this);
   if (mTrackBuffer && !IsInfinite(aStart)) {
     int64_t start = aStart * USECS_PER_S;
     int64_t end = IsInfinite(aEnd) ? INT64_MAX : (int64_t)(aEnd * USECS_PER_S);
     mTrackBuffer->RangeRemoval(start, end);
   }
-
-  StopUpdating();
 }
 
 void
 SourceBuffer::Detach()
 {
   MOZ_ASSERT(NS_IsMainThread());
   MSE_DEBUG("SourceBuffer(%p)::Detach", this);
   AbortBufferAppend();

--- a/dom/media/mediasource/SourceBuffer.h
+++ b/dom/media/mediasource/SourceBuffer.h
@@ -108,29 +108,30 @@ public:
 
   // Evict data in the source buffer in the given time range.
   void Evict(double aStart, double aEnd);
 
   double GetBufferedStart();
   double GetBufferedEnd();
 
   // Runs the range removal algorithm as defined by the MSE spec.
-  // RangeRemoval will queue a call to DoRangeRemoval.
   void RangeRemoval(double aStart, double aEnd);
+  // Actually remove data between aStart and aEnd
   void DoRangeRemoval(double aStart, double aEnd);
 
 #if defined(DEBUG)
   void Dump(const char* aPath);
 #endif
 
 private:
   ~SourceBuffer();
 
   friend class AsyncEventRunner<SourceBuffer>;
   friend class AppendDataRunnable;
+  friend class RangeRemovalRunnable;
   void DispatchSimpleEvent(const char* aName);
   void QueueAsyncSimpleEvent(const char* aName);
 
   // Update mUpdating and fire the appropriate events.
   void StartUpdating();
   void StopUpdating();
   void AbortUpdating();