--- a/gfx/2d/Factory.cpp
+++ b/gfx/2d/Factory.cpp
@@ -543,21 +543,22 @@ Factory::SetDirect3D10Device(ID3D10Devic
   // On Windows 8 error codes are the default, but on Windows 7 the
   // default is to throw (or perhaps only with some drivers?)
   aDevice->SetExceptionMode(0);
   mD3D10Device = aDevice;
 }
 
 ID3D10Device1*
 Factory::GetDirect3D10Device()
-
 {
 #ifdef DEBUG
-  UINT mode = mD3D10Device->GetExceptionMode();
-  MOZ_ASSERT(0 == mode);
+  if (mD3D10Device) {
+    UINT mode = mD3D10Device->GetExceptionMode();
+    MOZ_ASSERT(0 == mode);
+  }
 #endif
   return mD3D10Device;
 }
 
 #ifdef USE_D2D1_1
 TemporaryRef<DrawTarget>
 Factory::CreateDrawTargetForD3D11Texture(ID3D11Texture2D *aTexture, SurfaceFormat aFormat)
 {