#include <string.h>
 #include <unistd.h>
 #include <sys/types.h>
+#include <X11/extensions/Xrandr.h>
 #include <X11/keysym.h>
 #include <X11/Xlib.h>
 #include <X11/Xutil.h>
 static Lock **locks;
 static int nscreens;
 static Bool running = True;
+static Bool rr;
+static int rrevbase;
+static int rrerrbase;
 
 static void
 die(const char *errstr, ...)
                                }
                        }
                        llen = len;
-               }
-               else for (screen = 0; screen < nscreens; screen++)
+               } else if (rr && ev.type == rrevbase + RRScreenChangeNotify) {
+                       XRRScreenChangeNotifyEvent *rre = (XRRScreenChangeNotifyEvent*)&ev;
+                       for (screen = 0; screen < nscreens; screen++) {
+                               if (locks[screen]->win == rre->window) {
+                                       XResizeWindow(dpy, locks[screen]->win, rre->width, rre->height);
+                                       XClearWindow(dpy, locks[screen]->win);
+                               }
+                       }
+               } else for (screen = 0; screen < nscreens; screen++)
                        XRaiseWindow(dpy, locks[screen]->win);
        }
 }
        invisible = XCreatePixmapCursor(dpy, lock->pmap, lock->pmap, &color, &color, 0, 0);
        XDefineCursor(dpy, lock->win, invisible);
        XMapRaised(dpy, lock->win);
+       if (rr)
+               XRRSelectInput(dpy, lock->win, RRScreenChangeNotifyMask);
        for (len = 1000; len; len--) {
                if (XGrabPointer(dpy, lock->root, False, ButtonPressMask | ButtonReleaseMask | PointerMotionMask,
                    GrabModeAsync, GrabModeAsync, None, invisible, CurrentTime) == GrabSuccess)
 
        if (!(dpy = XOpenDisplay(0)))
                die("slock: cannot open display\n");
+       rr = XRRQueryExtension(dpy, &rrevbase, &rrerrbase);
        /* Get the number of screens in display "dpy" and blank them all. */
        nscreens = ScreenCount(dpy);
        locks = malloc(sizeof(Lock *) * nscreens);