diff --git a/hw/xwin/wintaskbar.c b/hw/xwin/wintaskbar.c
index 7dd4ec30bc..401ec175a2 100644
--- a/hw/xwin/wintaskbar.c
+++ b/hw/xwin/wintaskbar.c
@@ -66,7 +66,7 @@ DECLARE_INTERFACE_(ITaskbarList, IUnknown)
    seem to be the case
 */
 
-void winShowWindowOnTaskbar(HWND hWnd, BOOL show)
+void winShowWindowOnTaskbar(HWND hWnd, Bool show)
 {
   ITaskbarList* pTaskbarList = NULL;
 
diff --git a/hw/xwin/winwindow.h b/hw/xwin/winwindow.h
index e3a5948503..65e4bea0c7 100644
--- a/hw/xwin/winwindow.h
+++ b/hw/xwin/winwindow.h
@@ -160,7 +160,7 @@ void
  winSetAppUserModelID(HWND hWnd, const char *AppID);
 
 void
- winShowWindowOnTaskbar(HWND hWnd, BOOL show);
+ winShowWindowOnTaskbar(HWND hWnd, Bool show);
 
 #endif                          /* XWIN_MULTIWINDOW */
 #endif