--- a/gfx/layers/d3d9/CompositorD3D9.cpp
+++ b/gfx/layers/d3d9/CompositorD3D9.cpp
@@ -747,17 +747,21 @@ CompositorD3D9::PaintToTarget()
 
   device()->CreateOffscreenPlainSurface(desc.Width, desc.Height,
                                         D3DFMT_A8R8G8B8, D3DPOOL_SYSTEMMEM,
                                         getter_AddRefs(destSurf), nullptr);
 
   device()->GetRenderTargetData(backBuff, destSurf);
 
   D3DLOCKED_RECT rect;
-  destSurf->LockRect(&rect, nullptr, D3DLOCK_READONLY);
+  HRESULT hr = destSurf->LockRect(&rect, nullptr, D3DLOCK_READONLY);
+  if (FAILED(hr) || !rect.pBits) {
+    gfxCriticalError() << "Failed to lock rect in paint to target D3D9 " << hexa(hr);
+    return;
+  }
   RefPtr<DataSourceSurface> sourceSurface =
     Factory::CreateWrappingDataSourceSurface((uint8_t*)rect.pBits,
                                              rect.Pitch,
                                              IntSize(desc.Width, desc.Height),
                                              SurfaceFormat::B8G8R8A8);
   mTarget->CopySurface(sourceSurface,
                        IntRect(0, 0, desc.Width, desc.Height),
                        IntPoint(-mTargetBounds.x, -mTargetBounds.y));

--- a/gfx/layers/d3d9/TextureD3D9.cpp
+++ b/gfx/layers/d3d9/TextureD3D9.cpp
@@ -187,19 +187,20 @@ TextureSourceD3D9::InitTextures(DeviceMa
 
   RefPtr<IDirect3DTexture9> tmpTexture =
     aDeviceManager->CreateTexture(aSize, aFormat, D3DPOOL_SYSTEMMEM, this);
   if (!tmpTexture) {
     return nullptr;
   }
 
   tmpTexture->GetSurfaceLevel(0, byRef(aSurface));
-  aSurface->LockRect(&aLockedRect, nullptr, 0);
-  if (!aLockedRect.pBits) {
-    NS_WARNING("Could not lock surface");
+  
+  HRESULT hr = aSurface->LockRect(&aLockedRect, nullptr, 0);
+  if (FAILED(hr) || !aLockedRect.pBits) {
+    gfxCriticalError() << "Failed to lock rect initialize texture in D3D9 " << hexa(hr);
     return nullptr;
   }
 
   return result;
 }
 
 /**
  * Helper method for DataToTexture and SurfaceToTexture.
@@ -702,17 +703,21 @@ CairoTextureClientD3D9::BorrowDrawTarget
       mSurface = nullptr;
       return nullptr;
     }
   } else {
     // gfxWindowsSurface don't support transparency so we can't use the d3d9
     // windows surface optimization.
     // Instead we have to use a gfxImageSurface and fallback for font drawing.
     D3DLOCKED_RECT rect;
-    mD3D9Surface->LockRect(&rect, nullptr, 0);
+    HRESULT hr = mD3D9Surface->LockRect(&rect, nullptr, 0);
+    if (FAILED(hr) || !rect.pBits) {
+      gfxCriticalError() << "Failed to lock rect borrowing the target in D3D9 " << hexa(hr);
+      return nullptr;
+    }
     mSurface = new gfxImageSurface((uint8_t*)rect.pBits, mSize,
                                    rect.Pitch, SurfaceFormatToImageFormat(mFormat));
     mLockRect = true;
   }
 
   mDrawTarget =
     gfxPlatform::GetPlatform()->CreateDrawTargetForSurface(mSurface, mSize);