diff --git a/vrclient_x64/cxx.h b/vrclient_x64/cxx.h
index 373af218..8037d7de 100644
--- a/vrclient_x64/cxx.h
+++ b/vrclient_x64/cxx.h
@@ -16,10 +16,17 @@
  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
  */
 
-#ifndef __WINE_CXX_H
-#define __WINE_CXX_H
+#include "windef.h"
+#include "winternl.h"
+#include "rtlsupportapi.h"
 #include "wine/asm.h"
 
+#ifdef __i386__
+#undef RTTI_USE_RVA
+#else
+#define RTTI_USE_RVA 1
+#endif
+
 #ifdef _WIN64
 
 #define VTABLE_ADD_FUNC(name) "\t.quad " THISCALL_NAME(name) "\n"
@@ -46,7 +53,7 @@
 
 #endif /* _WIN64 */
 
-#ifndef __x86_64__
+#ifndef RTTI_USE_RVA
 
 #define DEFINE_RTTI_BASE(name, base_classes_no, mangled_name) \
     static type_info name ## _type_info = { \
@@ -101,7 +108,7 @@ static const cxx_type_info type ## _cxx_type_info = { \
     & type ##_type_info, \
     { 0, -1, 0 }, \
     sizeof(type), \
-    (cxx_copy_ctor)THISCALL(type ##_copy_ctor) \
+    THISCALL(type ##_copy_ctor) \
 };
 
 #define DEFINE_CXX_DATA(type, base_no, cl1, cl2, cl3, cl4, dtor)  \
@@ -118,9 +125,9 @@ static const cxx_type_info_table type ## _cxx_type_table = { \
     } \
 }; \
 \
-static const cxx_exception_type type ## _cxx_type = { \
+static const cxx_exception_type type ## _exception_type = { \
     0, \
-    (cxx_copy_ctor)THISCALL(dtor), \
+    THISCALL(dtor), \
     NULL, \
     & type ## _cxx_type_table \
 };
@@ -232,7 +239,7 @@ static cxx_type_info_table type ## _cxx_type_table = { \
     } \
 }; \
 \
-static cxx_exception_type type ##_cxx_type = { \
+static cxx_exception_type type ##_exception_type = { \
     0, \
     0xdeadbeef, \
     0, \
@@ -247,8 +254,8 @@ static void init_ ## type ## _cxx(char *base) \
     type ## _cxx_type_table.info[2]   = (char *)cl2 - base; \
     type ## _cxx_type_table.info[3]   = (char *)cl3 - base; \
     type ## _cxx_type_table.info[4]   = (char *)cl4 - base; \
-    type ## _cxx_type.destructor      = (char *)dtor - base; \
-    type ## _cxx_type.type_info_table = (char *)&type ## _cxx_type_table - base; \
+    type ## _exception_type.destructor      = (char *)dtor - base; \
+    type ## _exception_type.type_info_table = (char *)&type ## _cxx_type_table - base; \
 }
 
 #endif
@@ -324,8 +331,6 @@ typedef struct __type_info
     char               mangled[128]; /* Variable length, but we declare it large enough for static RTTI */
 } type_info;
 
-extern const vtable_ptr type_info_vtable;
-
 /* offsets for computing the this pointer */
 typedef struct
 {
@@ -334,10 +339,7 @@ typedef struct
     int         vbase_offset;  /* offset of this pointer offset in virtual base class descriptor */
 } this_ptr_offsets;
 
-/* dlls/msvcrt/cppexcept.h */
-typedef void (*cxx_copy_ctor)(void);
-
-#ifndef __x86_64__
+#ifndef RTTI_USE_RVA
 
 typedef struct _rtti_base_descriptor
 {
@@ -375,7 +377,7 @@ typedef struct
     const type_info *type_info;
     this_ptr_offsets offsets;
     unsigned int size;
-    cxx_copy_ctor copy_ctor;
+    void *copy_ctor;
 } cxx_type_info;
 
 typedef struct
@@ -387,8 +389,8 @@ typedef struct
 typedef struct
 {
     UINT flags;
-    void (*destructor)(void);
-    void* /*cxx_exc_custom_handler*/ custom_handler;
+    void *destructor;
+    void *custom_handler;
     const cxx_type_info_table *type_info_table;
 } cxx_exception_type;
 
@@ -450,6 +452,35 @@ typedef struct
 
 #endif
 
+extern const vtable_ptr type_info_vtable;
+
+#ifdef RTTI_USE_RVA
+
+static inline uintptr_t rtti_rva_base( const void *ptr )
+{
+    void *base;
+    return (uintptr_t)RtlPcToFileHeader( (void *)ptr, &base );
+}
+
+static inline void *rtti_rva( unsigned int rva, uintptr_t base )
+{
+    return (void *)(base + rva);
+}
+
+#else
+
+static inline uintptr_t rtti_rva_base( const void *ptr )
+{
+    return 0;
+}
+
+static inline void *rtti_rva( const void *ptr, uintptr_t base )
+{
+    return (void *)ptr;
+}
+
+#endif
+
 #define CREATE_TYPE_INFO_VTABLE \
 DEFINE_THISCALL_WRAPPER(type_info_vector_dtor,8) \
 void * __thiscall type_info_vector_dtor(type_info * _this, unsigned int flags) \
@@ -476,5 +507,3 @@ __ASM_BLOCK_BEGIN(type_info_vtables) \
     __ASM_VTABLE(type_info, \
             VTABLE_ADD_FUNC(type_info_vector_dtor)); \
 __ASM_BLOCK_END
-
-#endif
diff --git a/vrclient_x64/flatapi.c b/vrclient_x64/flatapi.c
index f7e4d510..a1a8be40 100644
--- a/vrclient_x64/flatapi.c
+++ b/vrclient_x64/flatapi.c
@@ -5,7 +5,6 @@
 #include "windef.h"
 #include "winbase.h"
 
-#include "cxx.h"
 #include "flatapi.h"
 
 #ifdef __i386__
diff --git a/vrclient_x64/flatapi.h b/vrclient_x64/flatapi.h
index c53d4447..99455d20 100644
--- a/vrclient_x64/flatapi.h
+++ b/vrclient_x64/flatapi.h
@@ -1,8 +1,9 @@
 /* asm thunks for the flat (FnTable) API */
 
+#include "vrclient_private.h"
+
 #ifdef __i386__
 
-#include "cxx.h"
 #include "pshpack1.h"
 struct thunk
 {
diff --git a/vrclient_x64/gen_wrapper.py b/vrclient_x64/gen_wrapper.py
index 9254644d..630ce4d9 100755
--- a/vrclient_x64/gen_wrapper.py
+++ b/vrclient_x64/gen_wrapper.py
@@ -1124,7 +1124,6 @@ def generate_flatapi_c():
 #include "windef.h"
 #include "winbase.h"
 
-#include "cxx.h"
 #include "flatapi.h"
 
 #ifdef __i386__
diff --git a/vrclient_x64/vrclient_private.h b/vrclient_x64/vrclient_private.h
index 174f88a4..5ef6cdc9 100644
--- a/vrclient_x64/vrclient_private.h
+++ b/vrclient_x64/vrclient_private.h
@@ -1,3 +1,6 @@
+#ifndef __VRCLIENT_PRIVATE_H
+#define __VRCLIENT_PRIVATE_H
+
 #include <stdarg.h>
 #include <stddef.h>
 #include <stdint.h>
@@ -123,3 +126,5 @@ extern w_Texture_t vrclient_translate_texture_d3d12( const w_Texture_t *texture,
 #include "vrclient_generated.h"
 
 #endif  /* __cplusplus */
+
+#endif /* __VRCLIENT_PRIVATE_H */