diff --git a/hw/xwayland/xwayland-output.c b/hw/xwayland/xwayland-output.c
index bfaf9795a..460caaf56 100644
--- a/hw/xwayland/xwayland-output.c
+++ b/hw/xwayland/xwayland-output.c
@@ -188,8 +188,11 @@ update_screen_size(struct xwl_output *xwl_output, int width, int height)
     SetRootClip(xwl_screen->screen, xwl_screen->root_clip_mode);
 
     if (xwl_screen->screen->root) {
+        BoxRec box = { 0, 0, width, height };
+
         xwl_screen->screen->root->drawable.width = width;
         xwl_screen->screen->root->drawable.height = height;
+        RegionReset(&xwl_screen->screen->root->winSize, &box);
         RRScreenSizeNotify(xwl_screen->screen);
     }
 
diff --git a/hw/xwayland/xwayland.c b/hw/xwayland/xwayland.c
index 993837f78..551443f93 100644
--- a/hw/xwayland/xwayland.c
+++ b/hw/xwayland/xwayland.c
@@ -443,9 +443,11 @@ xwl_realize_window(WindowPtr window)
     screen->RealizeWindow = xwl_realize_window;
 
     if (xwl_screen->rootless && !window->parent) {
+        BoxRec box = { 0, 0, xwl_screen->width, xwl_screen->height };
+
+        RegionReset(&window->winSize, &box);
         RegionNull(&window->clipList);
         RegionNull(&window->borderClip);
-        RegionNull(&window->winSize);
     }
 
     if (xwl_screen->rootless) {