diff --git a/programs/regedit/edit.c b/programs/regedit/edit.c
index 36946278247..6ccce00ce5f 100644
--- a/programs/regedit/edit.c
+++ b/programs/regedit/edit.c
@@ -64,7 +64,7 @@ static int vmessagebox(HWND hwnd, int buttons, int titleId, int resId, __ms_va_l
     return ret;
 }
 
-int __cdecl messagebox(HWND hwnd, int buttons, int titleId, int resId, ...)
+int WINAPIV messagebox(HWND hwnd, int buttons, int titleId, int resId, ...)
 {
     __ms_va_list ap;
     INT result;
@@ -76,7 +76,7 @@ int __cdecl messagebox(HWND hwnd, int buttons, int titleId, int resId, ...)
     return result;
 }
 
-static void __cdecl error_code_messagebox(HWND hwnd, unsigned int msg_id, ...)
+static void WINAPIV error_code_messagebox(HWND hwnd, unsigned int msg_id, ...)
 {
     __ms_va_list ap;
 
diff --git a/programs/regedit/main.h b/programs/regedit/main.h
index 8e05888883f..788de1a5098 100644
--- a/programs/regedit/main.h
+++ b/programs/regedit/main.h
@@ -160,7 +160,7 @@ extern BOOL DeleteKey(HWND hwnd, HKEY hKeyRoot, LPCWSTR keyPath);
 extern BOOL DeleteValue(HWND hwnd, HKEY hKeyRoot, LPCWSTR keyPath, LPCWSTR valueName, BOOL showMessageBox);
 extern BOOL RenameValue(HWND hwnd, HKEY hRootKey, LPCWSTR keyPath, LPCWSTR oldName, LPCWSTR newName);
 extern BOOL RenameKey(HWND hwnd, HKEY hRootKey, LPCWSTR keyPath, LPCWSTR newName);
-extern int __cdecl messagebox(HWND hwnd, int buttons, int titleId, int resId, ...);
+extern int WINAPIV messagebox(HWND hwnd, int buttons, int titleId, int resId, ...);
 
 /* hexedit.c */
 extern void HexEdit_Register(void);
diff --git a/programs/regedit/regedit.c b/programs/regedit/regedit.c
index 4dd71ca38f9..2d724f9bdfe 100644
--- a/programs/regedit/regedit.c
+++ b/programs/regedit/regedit.c
@@ -67,7 +67,7 @@ static void output_formatstring(const WCHAR *fmt, __ms_va_list va_args)
     LocalFree(str);
 }
 
-void __cdecl output_message(unsigned int id, ...)
+void WINAPIV output_message(unsigned int id, ...)
 {
     WCHAR fmt[1536];
     __ms_va_list va_args;
@@ -82,7 +82,7 @@ void __cdecl output_message(unsigned int id, ...)
     __ms_va_end(va_args);
 }
 
-void __cdecl error_exit(unsigned int id, ...)
+void WINAPIV error_exit(unsigned int id, ...)
 {
     WCHAR fmt[1536];
     __ms_va_list va_args;
diff --git a/programs/regedit/regproc.h b/programs/regedit/regproc.h
index 4031255ec33..9364fde7ec3 100644
--- a/programs/regedit/regproc.h
+++ b/programs/regedit/regproc.h
@@ -24,8 +24,8 @@
 #define REG_FORMAT_5 1
 #define REG_FORMAT_4 2
 
-void __cdecl output_message(unsigned int id, ...);
-void __cdecl error_exit(unsigned int id, ...);
+void WINAPIV output_message(unsigned int id, ...);
+void WINAPIV error_exit(unsigned int id, ...);
 
 char *GetMultiByteString(const WCHAR *strW);
 void *heap_xalloc(size_t size);