diff --git a/include/X11/Xlib.h b/include/X11/Xlib.h
index a26789b..e8aaae6 100644
--- a/include/X11/Xlib.h
+++ b/include/X11/Xlib.h
@@ -36,6 +36,9 @@ in this Software without prior written authorization from The Open Group.
 #ifndef _XLIB_H_
 #define _XLIB_H_
 
+/* whether users can set and get a pointer to private data */
+#define XLIB_DISPLAY_DATA
+
 #define XlibSpecificationRelease 6
 
 #ifdef USG
@@ -4003,6 +4006,12 @@ extern int _Xwctomb(
     wchar_t			/* wc */
 );
 
+/* whether users can set and get a pointer to private data */
+#ifdef XLIB_DISPLAY_DATA
+extern void *XGetDisplayData (Display *dpy);
+extern Bool XSetDisplayData (Display *dpy, const void *data);
+#endif /* XLIB_DISPLAY_DATA */
+
 _XFUNCPROTOEND
 
 #endif /* _XLIB_H_ */
diff --git a/include/X11/Xlibint.h b/include/X11/Xlibint.h
index 8aab764..11c5522 100644
--- a/include/X11/Xlibint.h
+++ b/include/X11/Xlibint.h
@@ -185,6 +185,9 @@ struct _XDisplay
 	struct _XkbInfoRec *xkb_info; /* XKB info */
 	struct _XtransConnInfo *trans_conn; /* transport connection object */
 	struct _X11XCBPrivate *xcb; /* XCB glue private data */
+#ifdef XLIB_DISPLAY_DATA
+  	void *data;		/* user supplied data */
+#endif /* XLIB_DISPLAY_DATA */
 };
 
 #define XAllocIDs(dpy,ids,n) (*(dpy)->idlist_alloc)(dpy,ids,n)
diff --git a/src/OpenDis.c b/src/OpenDis.c
index 9c327d1..8587688 100644
--- a/src/OpenDis.c
+++ b/src/OpenDis.c
@@ -84,6 +84,28 @@ static Bool _XBigReqHandler(Display *dpy, xReply *rep, char *buf, int len,
 				XPointer data);
 #endif /* !USE_XCB */
 
+#ifdef XLIB_DISPLAY_DATA
+void *
+XGetDisplayData (Display *dpy)
+{
+  if (dpy != 0 && dpy->data != 0)
+    return dpy->data;
+
+  return NULL;
+}
+
+Bool
+XSetDisplayData (Display *dpy, const void *data)
+{
+  if (dpy != 0 && data != 0)
+    {
+      dpy->data = data;
+      return False;
+    }
+  return True;
+}
+#endif /* XLIB_DISPLAY_DATA */
+
 /* 
  * Connects to a server, creates a Display object and returns a pointer to
  * the newly created Display back to the caller.