diff --git a/src/d3d9/d3d9_swapchain.cpp b/src/d3d9/d3d9_swapchain.cpp
index cbe47431a..fc36547d6 100644
--- a/src/d3d9/d3d9_swapchain.cpp
+++ b/src/d3d9/d3d9_swapchain.cpp
@@ -1046,7 +1046,7 @@ namespace dxvk {
   
   
   HRESULT D3D9SwapChainEx::LeaveFullscreenMode() {
-    if (!IsWindow(m_window))
+    if (!wsi::isWindow(m_window))
       return D3DERR_INVALIDCALL;
     
     if (FAILED(RestoreDisplayMode(m_monitor)))