diff --git a/demo/d3d11/main.c b/demo/d3d11/main.c
index bca37f4..a7abf1d 100644
--- a/demo/d3d11/main.c
+++ b/demo/d3d11/main.c
@@ -94,7 +94,7 @@ set_swap_chain_size(int width, int height)
     desc.Format = DXGI_FORMAT_R8G8B8A8_UNORM;
     desc.ViewDimension = D3D11_RTV_DIMENSION_TEXTURE2D;
 
-    hr = IDXGISwapChain_GetBuffer(swap_chain, 0, &IID_ID3D11Texture2D, &back_buffer);
+    hr = IDXGISwapChain_GetBuffer(swap_chain, 0, &IID_ID3D11Texture2D, (void **)&back_buffer);
     assert(SUCCEEDED(hr));
 
     hr = ID3D11Device_CreateRenderTargetView(device, (ID3D11Resource *)back_buffer, &desc, &rt_view);