diff --git a/kitty/glfw.c b/kitty/glfw.c
index 6874575c5..ab3556ccb 100644
--- a/kitty/glfw.c
+++ b/kitty/glfw.c
@@ -44,10 +44,20 @@ update_os_window_viewport(OSWindow *window, bool notify_boss) {
     if (fw == window->viewport_width && fh == window->viewport_height && w == window->window_width && h == window->window_height) {
         return; // no change, ignore
     }
-    if (fw / w > 5 || fh / h > 5 || fw < min_width || fh < min_height || fw < w || fh < h) {
+    if (w <= 0 || h <= 0 || fw / w > 5 || fh / h > 5 || fw < min_width || fh < min_height || fw < w || fh < h) {
         log_error("Invalid geometry ignored: framebuffer: %dx%d window: %dx%d\n", fw, fh, w, h);
+        if (!window->viewport_updated_at_least_once) {
+            window->viewport_width = min_width; window->viewport_height = min_height;
+            window->window_width = min_width; window->window_height = min_height;
+            window->viewport_x_ratio = 1; window->viewport_y_ratio = 1;
+            window->viewport_size_dirty = true;
+            if (notify_boss) {
+                call_boss(on_window_resize, "KiiO", window->id, window->viewport_width, window->viewport_height, Py_False);
+            }
+        }
         return;
     }
+    window->viewport_updated_at_least_once = true;
     window->viewport_width = fw; window->viewport_height = fh;
     double xr = window->viewport_x_ratio, yr = window->viewport_y_ratio;
     window->viewport_x_ratio = w > 0 ? (double)window->viewport_width / (double)w : xr;
@@ -59,8 +69,8 @@ update_os_window_viewport(OSWindow *window, bool notify_boss) {
     window->viewport_size_dirty = true;
     window->viewport_width = MAX(window->viewport_width, min_width);
     window->viewport_height = MAX(window->viewport_height, min_height);
-    window->window_width = MAX(w, 100);
-    window->window_height = MAX(h, 100);
+    window->window_width = MAX(w, min_width);
+    window->window_height = MAX(h, min_height);
     if (notify_boss) {
         call_boss(on_window_resize, "KiiO", window->id, window->viewport_width, window->viewport_height, dpi_changed ? Py_True : Py_False);
     }
diff --git a/kitty/state.h b/kitty/state.h
index 1297ef447..ec2f41ef4 100644
--- a/kitty/state.h
+++ b/kitty/state.h
@@ -140,7 +140,7 @@ typedef struct {
     bool mouse_button_pressed[20];
     PyObject *window_title;
     bool is_key_pressed[MAX_KEY_COUNT];
-    bool viewport_size_dirty;
+    bool viewport_size_dirty, viewport_updated_at_least_once;
     LiveResizeInfo live_resize;
     bool has_pending_resizes, is_semi_transparent, shown_once, is_damaged;
     uint32_t offscreen_texture_id;