diff --git a/source/dllmain.cpp b/source/dllmain.cpp
index 3b77866..22320a4 100644
--- a/source/dllmain.cpp
+++ b/source/dllmain.cpp
@@ -447,7 +447,7 @@ int WINAPI Direct3D9EnableMaximizedWindowedModeShim(BOOL mEnable)
 {
 	if (!m_pDirect3D9EnableMaximizedWindowedModeShim)
 	{
-		return E_FAIL;
+		return NULL;
 	}
 
 	return m_pDirect3D9EnableMaximizedWindowedModeShim(mEnable);