diff --git a/hw/xnest/Xnest.h b/hw/xnest/Xnest.h
index 8fd0066c2..d24491206 100644
--- a/hw/xnest/Xnest.h
+++ b/hw/xnest/Xnest.h
@@ -68,6 +68,7 @@ typedef XID KeySym64;
 #endif  /*_XSERVER64*/
 
 #include <X11/Xlib.h>
+#include <X11/Xlibint.h>
 #include <X11/Xutil.h>
 #include <X11/extensions/shape.h>
 #include <X11/Xlib-xcb.h>
diff --git a/hw/xnest/xcb.c b/hw/xnest/xcb.c
index a93628886..18fbc09ff 100644
--- a/hw/xnest/xcb.c
+++ b/hw/xnest/xcb.c
@@ -10,8 +10,11 @@
 #include <X11/Xdefs.h>
 #include <X11/Xproto.h>
 
+#include "include/gc.h"
+
 #include "Xnest.h"
 #include "xnest-xcb.h"
+#include "XNGC.h"
 
 #include "Display.h"
 
@@ -29,3 +32,15 @@ void xnest_upstream_setup(void) {
         xcb_screen_next (&iter);
     xnestUpstreamInfo.screenInfo = iter.data;
 }
+
+/* retrieve upstream GC XID for our xserver GC */
+uint32_t xnest_upstream_gc(GCPtr pGC) {
+    if (pGC == NULL) return 0;
+
+    xnestPrivGC *priv = dixLookupPrivate(&(pGC)->devPrivates, xnestGCPrivateKey);
+    if ((priv == NULL) || (priv->gc == NULL)) return 0;
+
+    // make sure Xlib's GC cache is written out before using (server side) GC.
+    XFlushGC(xnestDisplay, priv->gc);
+    return priv->gc->gid;
+}
diff --git a/hw/xnest/xnest-xcb.h b/hw/xnest/xnest-xcb.h
index 391e84d22..3c35e04dc 100644
--- a/hw/xnest/xnest-xcb.h
+++ b/hw/xnest/xnest-xcb.h
@@ -19,4 +19,7 @@ extern struct xnest_upstream_info xnestUpstreamInfo;
 /* fetch upstream connection's xcb setup data */
 void xnest_upstream_setup(void);
 
+/* retrieve upstream GC XID for our xserver GC */
+uint32_t xnest_upstream_gc(GCPtr pGC);
+
 #endif /* __XNEST__XCB_H */