diff --git a/src/pyopencl_ext.h b/src/pyopencl_ext.h
new file mode 100644
index 0000000000000000000000000000000000000000..a9792d8b07cb5be7a2def7d0b4a50941639442e1
--- /dev/null
+++ b/src/pyopencl_ext.h
@@ -0,0 +1,58 @@
+#ifndef _PYOPENCL_EXT_H
+#define _PYOPENCL_EXT_H
+
+#ifdef PYOPENCL_USE_SHIPPED_EXT
+
+#include "clinfo_ext.h"
+
+#else
+
+#if (defined(__APPLE__) && !defined(PYOPENCL_APPLE_USE_CL_H))
+
+#include <OpenCL/opencl.h>
+
+#else
+
+#include <CL/cl.h>
+#include <CL/cl_ext.h>
+
+#endif
+
+#ifndef CL_DEVICE_TOPOLOGY_TYPE_PCIE_AMD
+#define CL_DEVICE_TOPOLOGY_TYPE_PCIE_AMD        1
+
+typedef union
+{
+    struct { cl_uint type; cl_uint data[5]; } raw;
+    struct { cl_uint type; cl_char unused[17]; cl_char bus; cl_char device; cl_char function; } pcie;
+} cl_device_topology_amd;
+#endif
+
+/* {{{ these NV defines are often missing from the system headers */
+
+#ifndef CL_DEVICE_KERNEL_EXEC_TIMEOUT_NV
+#define CL_DEVICE_KERNEL_EXEC_TIMEOUT_NV                0x4005
+#endif
+#ifndef CL_DEVICE_INTEGRATED_MEMORY_NV
+#define CL_DEVICE_INTEGRATED_MEMORY_NV                  0x4006
+#endif
+
+#ifndef CL_DEVICE_ATTRIBUTE_ASYNC_ENGINE_COUNT_NV
+#define CL_DEVICE_ATTRIBUTE_ASYNC_ENGINE_COUNT_NV       0x4007
+#endif
+
+#ifndef CL_DEVICE_PCI_BUS_ID_NV
+#define CL_DEVICE_PCI_BUS_ID_NV                         0x4008
+#endif
+
+#ifndef CL_DEVICE_PCI_SLOT_ID_NV
+#define CL_DEVICE_PCI_SLOT_ID_NV                        0x4009
+#endif
+
+/* }}} */
+
+#endif
+
+#endif
+
+/* vim: foldmethod=marker */
diff --git a/src/wrap_cl.hpp b/src/wrap_cl.hpp
index 297186de66dcbc7793077bfdee4fac915f93fa00..9488a7155ca41a2d89c9cc4336c7e28f43b31d26 100644
--- a/src/wrap_cl.hpp
+++ b/src/wrap_cl.hpp
@@ -28,7 +28,7 @@
 #define CL_TARGET_OPENCL_VERSION 220
 
 #include <CL/cl.h>
-#include <CL/cl_ext.h>
+#include "pyopencl_ext.h"
 
 #if defined(_WIN32)
 #define NOMINMAX