diff --git a/dlls/d3dx9_36/math.c b/dlls/d3dx9_36/math.c
index 12073e3ed59..e09dbecbfdb 100644
--- a/dlls/d3dx9_36/math.c
+++ b/dlls/d3dx9_36/math.c
@@ -877,7 +877,7 @@ D3DXMATRIX* WINAPI D3DXMatrixTranspose(D3DXMATRIX *pout, CONST D3DXMATRIX *pm)
 
 static const unsigned int INITIAL_STACK_SIZE = 32;
 
-HRESULT WINAPI D3DXCreateMatrixStack(DWORD flags, LPD3DXMATRIXSTACK *ppstack)
+HRESULT WINAPI D3DXCreateMatrixStack(DWORD flags, ID3DXMatrixStack **ppstack)
 {
     struct ID3DXMatrixStackImpl *object;
 
diff --git a/include/d3dx9math.h b/include/d3dx9math.h
index 0f5dc7c6bab..769e0864f57 100644
--- a/include/d3dx9math.h
+++ b/include/d3dx9math.h
@@ -451,7 +451,7 @@ DECLARE_INTERFACE_(ID3DXMatrixStack, IUnknown)
 extern "C" {
 #endif
 
-HRESULT WINAPI D3DXCreateMatrixStack(DWORD flags, LPD3DXMATRIXSTACK* ppstack);
+HRESULT WINAPI D3DXCreateMatrixStack(DWORD flags, ID3DXMatrixStack **stack);
 
 #ifdef __cplusplus
 }