--- a/slock.c
+++ b/slock.c
@@ -286,7 +286,11 @@
 	int nlocks = 0;
 	for(screen = 0; screen < nscreens; screen++) {
 		if ( (locks[screen] = lockscreen(dpy, screen)) != NULL)
+		{
+			XSetWindowBackground(dpy, locks[screen]->win, locks[screen]->colors[0]);
+			XClearWindow(dpy, locks[screen]->win);
 			nlocks++;
+		}
 	}
 	XSync(dpy, False);