diff --git a/src/OpenDis.c b/src/OpenDis.c
index d8be825..9c327d1 100644
--- a/src/OpenDis.c
+++ b/src/OpenDis.c
@@ -882,6 +882,10 @@ void _XFreeDisplayStructure(dpy)
  	    Xfree (dpy->scratch_buffer);
 	FreeDisplayLock(dpy);
 
+#if USE_XCB
+	_XCBShutdownDisplayLock(dpy);
+#endif /* USE_XCB */
+
 	if (dpy->qfree) {
 	    register _XQEvent *qelt = dpy->qfree;
 
diff --git a/src/Xxcbint.h b/src/Xxcbint.h
index 956c891..cc73749 100644
--- a/src/Xxcbint.h
+++ b/src/Xxcbint.h
@@ -45,6 +45,7 @@ void _XFreeX11XCBStructure(Display *dpy);
 /* xcb_lock.c */
 
 int _XCBInitDisplayLock(Display *dpy);
+void _XCBShutdownDisplayLock(Display *dpy);
 
 /* _XGetXCBBuffer and _XPutXCBBuffer calls must be paired and must not
  * be nested. */
diff --git a/src/xcb_lock.c b/src/xcb_lock.c
index fab8b44..0ace8e5 100644
--- a/src/xcb_lock.c
+++ b/src/xcb_lock.c
@@ -47,6 +47,14 @@ int _XCBInitDisplayLock(Display *dpy)
     return 1;
 }
 
+void _XCBShutdownDisplayLock(Display *dpy)
+{
+    if(dpy->lock_fns) {
+	Xfree((char *)dpy->lock_fns);
+	dpy->lock_fns = NULL;
+    }
+}
+
 void _XGetXCBBuffer(Display *dpy)
 {
     static const xReq dummy_request;