diff --git a/mi/mioverlay.c b/mi/mioverlay.c
index b997322a5..0c1d79d70 100644
--- a/mi/mioverlay.c
+++ b/mi/mioverlay.c
@@ -58,14 +58,9 @@ typedef struct {
 static DevPrivateKeyRec miOverlayWindowKeyRec;
 
 #define miOverlayWindowKey (&miOverlayWindowKeyRec)
-static DevPrivateKeyRec miOverlayScreenKeyRec;
-
-#define miOverlayScreenKey (&miOverlayScreenKeyRec)
 
 static void MarkUnderlayWindow(WindowPtr);
 
-#define MIOVERLAY_GET_SCREEN_PRIVATE(pScreen) ((miOverlayScreenPtr) \
-	dixLookupPrivate(&(pScreen)->devPrivates, miOverlayScreenKey))
 #define MIOVERLAY_GET_WINDOW_PRIVATE(pWin) ((miOverlayWindowPtr) \
 	dixLookupPrivate(&(pWin)->devPrivates, miOverlayWindowKey))
 #define MIOVERLAY_GET_WINDOW_TREE(pWin) \
@@ -102,12 +97,6 @@ miOverlaySetRootClip(ScreenPtr pScreen, Bool enable)
 
 /****************************************************************/
 
-void
-miOverlaySetTransFunction(ScreenPtr pScreen, miOverlayTransFunc transFunc)
-{
-    MIOVERLAY_GET_SCREEN_PRIVATE(pScreen)->MakeTransparent = transFunc;
-}
-
 static void
 MarkUnderlayWindow(WindowPtr pWin)
 {
diff --git a/mi/mioverlay.h b/mi/mioverlay.h
index a1e38e596..68a88260a 100644
--- a/mi/mioverlay.h
+++ b/mi/mioverlay.h
@@ -9,7 +9,6 @@
 typedef void (*miOverlayTransFunc) (ScreenPtr, int, BoxPtr);
 typedef Bool (*miOverlayInOverlayFunc) (WindowPtr);
 
-extern _X_EXPORT void miOverlaySetTransFunction(ScreenPtr, miOverlayTransFunc);
 extern _X_EXPORT void miOverlaySetRootClip(ScreenPtr, Bool);
 
 #endif                          /* __MIOVERLAY_H */