diff --git a/dix/window_priv.h b/dix/window_priv.h
index e01c46fd5..947448f8a 100644
--- a/dix/window_priv.h
+++ b/dix/window_priv.h
@@ -39,6 +39,10 @@
 
 #define SameBorder(as, a, bs, b) EqualPixUnion(as, a, bs, b)
 
+extern Mask DontPropagateMasks[];
+
+#define wDontPropagateMask(w)   wUseDefault(w, dontPropagateMask, DontPropagateMasks[(w)->dontPropagate])
+
 /*
  * @brief create a window
  *
diff --git a/include/windowstr.h b/include/windowstr.h
index 2eb0dda29..fd18691bf 100644
--- a/include/windowstr.h
+++ b/include/windowstr.h
@@ -156,8 +156,6 @@ typedef struct _Window {
     PropertyPtr properties;     /* default: NULL */
 } WindowRec;
 
-extern _X_EXPORT Mask DontPropagateMasks[];
-
 #define wBorderWidth(w)		((int) (w)->borderWidth)
 
 static inline PropertyPtr wUserProps(WindowPtr pWin) { return pWin->properties; }