--- slock.c
+++ slock.c
@@ -186,7 +186,7 @@ readpw(Display *dpy, struct xrandr *rr, struct lock **locks, int nscreens,
 			case XF86XK_AudioStop:
 			case XF86XK_AudioPrev:
 			case XF86XK_AudioNext:
-				XSendEvent(dpy, locks[0]->root, True, KeyPressMask, &ev);
+				XSendEvent(dpy, DefaultRootWindow(dpy), True, KeyPressMask, &ev);
 				break;
 			case XK_Return:
 				passwd[len] = '\0';