--- a/gfx/layers/D3D11YCbCrImage.cpp
+++ b/gfx/layers/D3D11YCbCrImage.cpp
@@ -284,19 +284,34 @@ D3D11YCbCrRecycleAllocator::Allocate(Sur
 
   gfx::IntSize YSize = mYSize.refOr(aSize);
   gfx::IntSize CbCrSize =
     mCbCrSize.refOr(gfx::IntSize(YSize.width, YSize.height));
   CD3D11_TEXTURE2D_DESC newDesc(DXGI_FORMAT_R8_UNORM, YSize.width, YSize.height,
                                 1, 1);
   newDesc.MiscFlags = D3D11_RESOURCE_MISC_SHARED_KEYEDMUTEX;
 
+  RefPtr<ID3D10Multithread> mt;
+  HRESULT hr = mDevice->QueryInterface(
+    (ID3D10Multithread**)getter_AddRefs(mt));
+
+  if (FAILED(hr) || !mt) {
+    gfxCriticalError() << "Multithread safety interface not supported. " << hr;
+    return nullptr;
+  }
+
+  if (!mt->GetMultithreadProtected()) {
+    gfxCriticalError() << "Device used not marked as multithread-safe.";
+    return nullptr;
+  }
+
+  D3D11MTAutoEnter mtAutoEnter(mt.forget());
+
   RefPtr<ID3D11Texture2D> textureY;
-  HRESULT hr =
-    mDevice->CreateTexture2D(&newDesc, nullptr, getter_AddRefs(textureY));
+  hr = mDevice->CreateTexture2D(&newDesc, nullptr, getter_AddRefs(textureY));
   NS_ENSURE_TRUE(SUCCEEDED(hr), nullptr);
 
   newDesc.Width = CbCrSize.width;
   newDesc.Height = CbCrSize.height;
 
   RefPtr<ID3D11Texture2D> textureCb;
   hr = mDevice->CreateTexture2D(&newDesc, nullptr, getter_AddRefs(textureCb));
   NS_ENSURE_TRUE(SUCCEEDED(hr), nullptr);