diff --git a/dlls/d3dx10_43/d3dx10_43.spec b/dlls/d3dx10_43/d3dx10_43.spec
index ab696e872ad..f410be8b832 100644
--- a/dlls/d3dx10_43/d3dx10_43.spec
+++ b/dlls/d3dx10_43/d3dx10_43.spec
@@ -70,7 +70,7 @@
 @ stdcall D3DXColorAdjustSaturation(ptr ptr float) d3dx9_36.D3DXColorAdjustSaturation
 @ stdcall D3DXComputeBoundingBox(ptr long long ptr ptr) d3dx9_36.D3DXComputeBoundingBox
 @ stdcall D3DXComputeBoundingSphere(ptr long long ptr ptr) d3dx9_36.D3DXComputeBoundingSphere
-@ stub D3DXCpuOptimizations(long)
+@ stdcall D3DXCpuOptimizations(long)
 @ stdcall D3DXCreateMatrixStack(long ptr) d3dx9_36.D3DXCreateMatrixStack
 @ stdcall D3DXFloat16To32Array(ptr ptr long) d3dx9_36.D3DXFloat16To32Array
 @ stdcall D3DXFloat32To16Array(ptr ptr long) d3dx9_36.D3DXFloat32To16Array
diff --git a/dlls/d3dx10_43/d3dx10_43_main.c b/dlls/d3dx10_43/d3dx10_43_main.c
index 0c1ff801e8c..7308373fa89 100644
--- a/dlls/d3dx10_43/d3dx10_43_main.c
+++ b/dlls/d3dx10_43/d3dx10_43_main.c
@@ -34,8 +34,7 @@
 #include "objbase.h"
 
 #include "d3d10_1.h"
-#include "d3dx10core.h"
-#include "d3dx10tex.h"
+#include "d3dx10.h"
 
 WINE_DEFAULT_DEBUG_CHANNEL(d3dx);
 
@@ -210,3 +209,10 @@ HRESULT WINAPI D3DX10GetImageInfoFromMemory(const void *src_data, SIZE_T src_dat
 
     return E_NOTIMPL;
 }
+
+D3DX_CPU_OPTIMIZATION WINAPI D3DXCpuOptimizations(BOOL enable)
+{
+    FIXME("enable %#x stub.\n", enable);
+
+    return D3DX_NOT_OPTIMIZED;
+}
diff --git a/include/Makefile.in b/include/Makefile.in
index 9c20f28a2de..4aaefaf8768 100644
--- a/include/Makefile.in
+++ b/include/Makefile.in
@@ -256,6 +256,7 @@ HEADER_SRCS = \
 	d3dvec.inl \
 	d3dx10.h \
 	d3dx10async.h \
+	d3dx10math.h \
 	d3dx10tex.h \
 	d3dx11.h \
 	d3dx11async.h \
diff --git a/include/d3dx10.h b/include/d3dx10.h
index dd423a53086..fb48723b5f3 100644
--- a/include/d3dx10.h
+++ b/include/d3dx10.h
@@ -27,6 +27,7 @@
 #define DXGI_FORMAT_FROM_FILE ((DXGI_FORMAT)0xfffffffdu)
 
 #include "d3d10.h"
+#include "d3dx10math.h"
 #include "d3dx10core.h"
 #include "d3dx10async.h"
 #include "d3dx10tex.h"
diff --git a/include/d3dx10math.h b/include/d3dx10math.h
new file mode 100644
index 00000000000..a96784b1089
--- /dev/null
+++ b/include/d3dx10math.h
@@ -0,0 +1,45 @@
+/*
+ * Copyright (C) 2016 Alistair Leslie-Hughes
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
+ */
+
+#include "d3dx10.h"
+
+/* This guard is the same as D3DX9 to prevent double-inclusion */
+#ifndef __D3DX9MATH_H__
+#define __D3DX9MATH_H__
+
+#include <math.h>
+
+typedef enum _D3DX_CPU_OPTIMIZATION
+{
+    D3DX_NOT_OPTIMIZED,
+    D3DX_3DNOW_OPTIMIZED,
+    D3DX_SSE2_OPTIMIZED,
+    D3DX_SSE_OPTIMIZED
+} D3DX_CPU_OPTIMIZATION;
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+D3DX_CPU_OPTIMIZATION WINAPI D3DXCpuOptimizations(BOOL enable);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* __D3DX9MATH_H__ */