diff --git a/hw/xwin/win.h b/hw/xwin/win.h
index 9fa697dcc..e89f730b0 100644
--- a/hw/xwin/win.h
+++ b/hw/xwin/win.h
@@ -717,8 +717,7 @@ void winSetAuthorization(void);
 
 void
 
-winBlockHandler(ScreenPtr pScreen,
-                void *pTimeout, void *pReadMask);
+winBlockHandler(ScreenPtr pScreen, void *pTimeout);
 
 #ifdef XWIN_CLIPBOARD
 /*
diff --git a/hw/xwin/winblock.c b/hw/xwin/winblock.c
index 8b846520c..110740d55 100644
--- a/hw/xwin/winblock.c
+++ b/hw/xwin/winblock.c
@@ -36,8 +36,7 @@
 
 /* See Porting Layer Definition - p. 6 */
 void
-winBlockHandler(ScreenPtr pScreen,
-                void *pTimeout, void *pReadMask)
+winBlockHandler(ScreenPtr pScreen, void *pTimeout)
 {
 #if defined(XWIN_CLIPBOARD) || defined(XWIN_MULTIWINDOW)
     winScreenPriv(pScreen);