diff --git a/gfx/d3d/render_chain_xdk.cpp b/gfx/d3d/render_chain_xdk.cpp
index 4135d5ff51..1163bc7cd7 100644
--- a/gfx/d3d/render_chain_xdk.cpp
+++ b/gfx/d3d/render_chain_xdk.cpp
@@ -397,7 +397,7 @@ static void xdk_renderchain_convert_geometry(
 	  void *data, const void *info_data,
       unsigned *out_width, unsigned *out_height,
       unsigned width, unsigned height,
-      D3DVIEWPORT *final_viewport)
+      void *final_viewport_data)
 {
    (void)data;
    (void)info_data;
@@ -405,7 +405,7 @@ static void xdk_renderchain_convert_geometry(
    (void)out_height;
    (void)width;
    (void)height;
-   (void)final_viewport;
+   (void)final_viewport_data;
    
    /* stub */
 }