diff --git a/hw/xwin/InitOutput.c b/hw/xwin/InitOutput.c
index 7faed0170..22ef8da76 100644
--- a/hw/xwin/InitOutput.c
+++ b/hw/xwin/InitOutput.c
@@ -49,7 +49,7 @@ from The Open Group.
 #endif
 #ifdef RELOCATE_PROJECTROOT
 #include <shlobj.h>
-typedef HRESULT (*SHGETFOLDERPATHPROC)(
+typedef WINAPI HRESULT (*SHGETFOLDERPATHPROC)(
     HWND hwndOwner,
     int nFolder,
     HANDLE hToken,
diff --git a/hw/xwin/winmonitors.c b/hw/xwin/winmonitors.c
index 63af803d0..a9d46f90e 100644
--- a/hw/xwin/winmonitors.c
+++ b/hw/xwin/winmonitors.c
@@ -53,7 +53,7 @@ wBOOL CALLBACK getMonitorInfo(HMONITOR hMonitor, HDC hdc, LPRECT rect, LPARAM _d
   return TRUE;
 }
 
-typedef wBOOL (*ENUMDISPLAYMONITORSPROC)(HDC,LPCRECT,MONITORENUMPROC,LPARAM);
+typedef WINAPI wBOOL (*ENUMDISPLAYMONITORSPROC)(HDC,LPCRECT,MONITORENUMPROC,LPARAM);
 ENUMDISPLAYMONITORSPROC _EnumDisplayMonitors;
 
 wBOOL CALLBACK getMonitorInfo(HMONITOR hMonitor, HDC hdc, LPRECT rect, LPARAM _data);