--- a/gfx/layers/D3D11ShareHandleImage.cpp
+++ b/gfx/layers/D3D11ShareHandleImage.cpp
@@ -123,16 +123,17 @@ D3D11ShareHandleImage::GetAsSourceSurfac
   if (FAILED(hr)) {
     NS_WARNING("Failed to create 2D staging texture.");
     return nullptr;
   }
 
   RefPtr<ID3D11DeviceContext> context;
   device->GetImmediateContext(getter_AddRefs(context));
   if (!context) {
+    gfxCriticalError() << "Failed to get immediate context.";
     return nullptr;
   }
 
   RefPtr<IDXGIKeyedMutex> mutex;
   hr = texture->QueryInterface((IDXGIKeyedMutex**)getter_AddRefs(mutex));
 
   if (SUCCEEDED(hr) && mutex) {
     hr = mutex->AcquireSync(0, 2000);

--- a/gfx/layers/D3D11YCbCrImage.cpp
+++ b/gfx/layers/D3D11YCbCrImage.cpp
@@ -68,16 +68,20 @@ D3D11YCbCrImage::SetData(KnowsCompositor
     gfxCriticalError() << "Device used not marked as multithread-safe.";
     return false;
   }
 
   D3D11MTAutoEnter mtAutoEnter(mt.forget());
 
   RefPtr<ID3D11DeviceContext> ctx;
   allocator->GetDevice()->GetImmediateContext(getter_AddRefs(ctx));
+  if (!ctx) {
+    gfxCriticalError() << "Failed to get immediate context.";
+    return false;
+  }
 
   AutoLockD3D11Texture lockY(textureY);
   AutoLockD3D11Texture lockCb(textureCb);
   AutoLockD3D11Texture lockCr(textureCr);
 
   ctx->UpdateSubresource(textureY,
                          0,
                          nullptr,
@@ -184,16 +188,20 @@ D3D11YCbCrImage::GetAsSourceSurface()
   desc.CPUAccessFlags = D3D11_CPU_ACCESS_READ;
   desc.Usage = D3D11_USAGE_STAGING;
 
   dev->CreateTexture2D(&desc, nullptr, getter_AddRefs(softTexCb));
   dev->CreateTexture2D(&desc, nullptr, getter_AddRefs(softTexCr));
 
   RefPtr<ID3D11DeviceContext> ctx;
   dev->GetImmediateContext(getter_AddRefs(ctx));
+  if (!ctx) {
+    gfxCriticalError() << "Failed to get immediate context.";
+    return nullptr;
+  }
 
   {
     AutoLockD3D11Texture lockY(texY);
     AutoLockD3D11Texture lockCb(texCb);
     AutoLockD3D11Texture lockCr(texCr);
     ctx->CopyResource(softTexY, texY);
     ctx->CopyResource(softTexCb, texCb);
     ctx->CopyResource(softTexCr, texCr);