diff --git a/docs/changelog.rst b/docs/changelog.rst
index 6bae033dc..2df4c7019 100644
--- a/docs/changelog.rst
+++ b/docs/changelog.rst
@@ -135,6 +135,9 @@ To update |kitty|, :doc:`follow the instructions <binary>`.
 
 - A new mappable action to close windows with a confirmation (:iss:`4195`)
 
+- When remembering OS window sizes for full screen windows use the size before
+  the window became fullscreen (:iss:`4221`)
+
 
 0.23.1 [2021-08-17]
 ----------------------
diff --git a/kitty/child-monitor.c b/kitty/child-monitor.c
index afb122c89..b386c7e20 100644
--- a/kitty/child-monitor.c
+++ b/kitty/child-monitor.c
@@ -929,8 +929,13 @@ process_pending_resizes(monotonic_t now) {
 
 static void
 close_os_window(ChildMonitor *self, OSWindow *os_window) {
+    int w = os_window->window_width, h = os_window->window_height;
+    if (os_window->before_fullscreen.is_set && is_os_window_fullscreen(os_window)) {
+        printf("11111111111111 w=%d h=%d bw: %d bh: %d\n", w, h, os_window->before_fullscreen.w, os_window->before_fullscreen.h);
+        w = os_window->before_fullscreen.w; h = os_window->before_fullscreen.h;
+    }
     destroy_os_window(os_window);
-    call_boss(on_os_window_closed, "Kii", os_window->id, os_window->window_width, os_window->window_height);
+    call_boss(on_os_window_closed, "Kii", os_window->id, w, h);
     for (size_t t=0; t < os_window->num_tabs; t++) {
         Tab *tab = os_window->tabs + t;
         for (size_t w = 0; w < tab->num_windows; w++) mark_child_for_close(self, tab->windows[w].id);
diff --git a/kitty/os_window_size.py b/kitty/os_window_size.py
index bcdd9d559..ad1c20503 100644
--- a/kitty/os_window_size.py
+++ b/kitty/os_window_size.py
@@ -31,6 +31,7 @@ class WindowSizeData(NamedTuple):
 
 def initial_window_size_func(opts: WindowSizeData, cached_values: Dict[str, Any]) -> Callable[[int, int, float, float, float, float], Tuple[int, int]]:
 
+    print(cached_values)
     if 'window-size' in cached_values and opts.remember_window_size:
         ws = cached_values['window-size']
         try: