diff --git a/dlls/msvcp90/cxx.h b/dlls/msvcp90/cxx.h
index fd697564afd..e14b7deaba5 100644
--- a/dlls/msvcp90/cxx.h
+++ b/dlls/msvcp90/cxx.h
@@ -18,29 +18,6 @@
 
 #include "wine/asm.h"
 
-/* Copied from dlls/msvcrt/cxx.h */
-#undef __thiscall
-#ifdef __i386__  /* thiscall functions are i386-specific */
-
-#define THISCALL(func) __thiscall_ ## func
-#define THISCALL_NAME(func) __ASM_NAME("__thiscall_" #func)
-#define __thiscall __stdcall
-#define DEFINE_THISCALL_WRAPPER(func,args) \
-    extern void THISCALL(func)(void); \
-    __ASM_GLOBAL_FUNC(__thiscall_ ## func, \
-                      "popl %eax\n\t" \
-                      "pushl %ecx\n\t" \
-                      "pushl %eax\n\t" \
-                      "jmp " __ASM_NAME(#func) __ASM_STDCALL(args) )
-#else /* __i386__ */
-
-#define THISCALL(func) func
-#define THISCALL_NAME(func) __ASM_NAME(#func)
-#define __thiscall __cdecl
-#define DEFINE_THISCALL_WRAPPER(func,args) /* nothing */
-
-#endif /* __i386__ */
-
 #ifdef _WIN64
 
 #define VTABLE_ADD_FUNC(name) "\t.quad " THISCALL_NAME(name) "\n"
diff --git a/dlls/msvcrt/cxx.h b/dlls/msvcrt/cxx.h
index 75677e28736..68783f5acd1 100644
--- a/dlls/msvcrt/cxx.h
+++ b/dlls/msvcrt/cxx.h
@@ -18,28 +18,6 @@
 
 #include "wine/asm.h"
 
-#undef __thiscall
-#ifdef __i386__  /* thiscall functions are i386-specific */
-
-#define THISCALL(func) __thiscall_ ## func
-#define THISCALL_NAME(func) __ASM_NAME("__thiscall_" #func)
-#define __thiscall __stdcall
-#define DEFINE_THISCALL_WRAPPER(func,args) \
-    extern void THISCALL(func)(void); \
-    __ASM_GLOBAL_FUNC(__thiscall_ ## func, \
-                      "popl %eax\n\t" \
-                      "pushl %ecx\n\t" \
-                      "pushl %eax\n\t" \
-                      "jmp " __ASM_NAME(#func) __ASM_STDCALL(args) )
-#else /* __i386__ */
-
-#define THISCALL(func) func
-#define THISCALL_NAME(func) __ASM_NAME(#func)
-#define __thiscall __cdecl
-#define DEFINE_THISCALL_WRAPPER(func,args) /* nothing */
-
-#endif /* __i386__ */
-
 #ifdef _WIN64
 
 #define VTABLE_ADD_FUNC(name) "\t.quad " THISCALL_NAME(name) "\n"
diff --git a/dlls/riched20/txthost.c b/dlls/riched20/txthost.c
index ab9450383d4..e4c4e0c180f 100644
--- a/dlls/riched20/txthost.c
+++ b/dlls/riched20/txthost.c
@@ -500,35 +500,6 @@ DECLSPEC_HIDDEN HRESULT WINAPI ITextHostImpl_TxGetSelectionBarWidth(ITextHost *i
 }
 
 
-#ifdef __i386__  /* thiscall functions are i386-specific */
-
-#define THISCALL(func) (void *) __thiscall_ ## func
-#ifdef _MSC_VER
-#define DEFINE_THISCALL_WRAPPER(func,args) \
-    __declspec(naked) HRESULT __thiscall_##func(void) \
-    { \
-        __asm pop eax \
-        __asm push ecx \
-        __asm push eax \
-        __asm jmp func \
-    }
-#else /* _MSC_VER */
-#define DEFINE_THISCALL_WRAPPER(func,args) \
-   extern HRESULT __thiscall_ ## func(void); \
-   __ASM_GLOBAL_FUNC(__thiscall_ ## func, \
-                   "popl %eax\n\t" \
-                   "pushl %ecx\n\t" \
-                   "pushl %eax\n\t" \
-                   "jmp " __ASM_NAME(#func) __ASM_STDCALL(args) )
-#endif /* _MSC_VER */
-
-#else /* __i386__ */
-
-#define THISCALL(func) func
-#define DEFINE_THISCALL_WRAPPER(func,args) /* nothing */
-
-#endif /* __i386__ */
-
 DEFINE_THISCALL_WRAPPER(ITextHostImpl_TxGetDC,4)
 DEFINE_THISCALL_WRAPPER(ITextHostImpl_TxReleaseDC,8)
 DEFINE_THISCALL_WRAPPER(ITextHostImpl_TxShowScrollBar,12)
diff --git a/dlls/riched20/txtsrv.c b/dlls/riched20/txtsrv.c
index a9ceef4dd1f..6777f97de4c 100644
--- a/dlls/riched20/txtsrv.c
+++ b/dlls/riched20/txtsrv.c
@@ -34,35 +34,6 @@
 #include "wine/debug.h"
 #include "editstr.h"
 
-#ifdef __i386__  /* thiscall functions are i386-specific */
-
-#define THISCALL(func) (void *) __thiscall_ ## func
-#ifdef _MSC_VER
-#define DEFINE_THISCALL_WRAPPER(func,args) \
-    __declspec(naked) HRESULT __thiscall_##func(void) \
-    { \
-        __asm pop eax \
-        __asm push ecx \
-        __asm push eax \
-        __asm jmp func \
-    }
-#else /* _MSC_VER */
-#define DEFINE_THISCALL_WRAPPER(func,args) \
-   extern HRESULT __thiscall_ ## func(void); \
-   __ASM_GLOBAL_FUNC(__thiscall_ ## func, \
-                   "popl %eax\n\t" \
-                   "pushl %ecx\n\t" \
-                   "pushl %eax\n\t" \
-                   "jmp " __ASM_NAME(#func) __ASM_STDCALL(args) )
-#endif /* _MSC_VER */
-
-#else /* __i386__ */
-
-#define THISCALL(func) func
-#define DEFINE_THISCALL_WRAPPER(func,args) /* nothing */
-
-#endif /* __i386__ */
-
 WINE_DEFAULT_DEBUG_CHANNEL(richedit);
 
 typedef struct ITextServicesImpl {
diff --git a/dlls/vssapi/main.c b/dlls/vssapi/main.c
index 2ebd2041f89..526772add19 100644
--- a/dlls/vssapi/main.c
+++ b/dlls/vssapi/main.c
@@ -28,28 +28,6 @@
 
 WINE_DEFAULT_DEBUG_CHANNEL( vssapi );
 
-#undef __thiscall
-#ifdef __i386__  /* thiscall functions are i386-specific */
-
-#define THISCALL(func) __thiscall_ ## func
-#define THISCALL_NAME(func) __ASM_NAME("__thiscall_" #func)
-#define __thiscall __stdcall
-#define DEFINE_THISCALL_WRAPPER(func,args) \
-    extern void THISCALL(func)(void); \
-    __ASM_GLOBAL_FUNC(__thiscall_ ## func, \
-                      "popl %eax\n\t" \
-                      "pushl %ecx\n\t" \
-                      "pushl %eax\n\t" \
-                      "jmp " __ASM_NAME(#func) __ASM_STDCALL(args) )
-#else /* __i386__ */
-
-#define THISCALL(func) func
-#define THISCALL_NAME(func) __ASM_NAME(#func)
-#define __thiscall __cdecl
-#define DEFINE_THISCALL_WRAPPER(func,args) /* nothing */
-
-#endif /* __i386__ */
-
 struct CVssWriter
 {
     void **vtable;
diff --git a/include/wine/asm.h b/include/wine/asm.h
index f1c50fd6ad6..a581b120da3 100644
--- a/include/wine/asm.h
+++ b/include/wine/asm.h
@@ -88,4 +88,41 @@
 
 #endif  /* __i386__ */
 
+/* thiscall support */
+
+#undef __thiscall
+#define __thiscall __stdcall
+
+#ifdef __i386__
+
+# ifdef _MSC_VER
+#  define DEFINE_THISCALL_WRAPPER(func,args) \
+    __declspec(naked) HRESULT __thiscall_##func(void) \
+    { __asm { \
+        pop eax \
+        push ecx \
+        push eax \
+        jmp func \
+    } }
+# else  /* _MSC_VER */
+#  define DEFINE_THISCALL_WRAPPER(func,args) \
+    extern void __thiscall_ ## func(void);  \
+    __ASM_GLOBAL_FUNC( __thiscall_ ## func, \
+                       "popl %eax\n\t"  \
+                       "pushl %ecx\n\t" \
+                       "pushl %eax\n\t" \
+                       "jmp " __ASM_NAME(#func) __ASM_STDCALL(args) )
+# endif  /* _MSC_VER */
+
+# define THISCALL(func) (void *)__thiscall_ ## func
+# define THISCALL_NAME(func) __ASM_NAME("__thiscall_" #func)
+
+#else  /* __i386__ */
+
+# define DEFINE_THISCALL_WRAPPER(func,args) /* nothing */
+# define THISCALL(func) func
+# define THISCALL_NAME(func) __ASM_NAME(#func)
+
+#endif  /* __i386__ */
+
 #endif  /* __WINE_WINE_ASM_H */