diff --git a/.config/sway/config b/.config/sway/config
index 1dbeefe..524e29d 100644
--- a/.config/sway/config
+++ b/.config/sway/config
@@ -240,6 +240,12 @@ for_window [class="vlc"]		border pixel 2 inhibit_idle visible fullscreen
 for_window [app_id="vlc"]		border pixel 2 inhibit_idle visible fullscreen
 for_window [title=".*VLC*."]		border pixel 2 inhibit_idle visible fullscreen
 for_window [title="VLC*."]		border pixel 2 inhibit_idle visible fullscreen
+
+# prevent screen locking if any app is fullscreen.
+# matching per-class is tedious.
+for_window [class=".*"] inhibit_idle fullscreen
+for_window [app_id=".*"] inhibit_idle fullscreen
+
 for_window [app_id="org.gnome.Nautilus"]		border pixel 1
 for_window [app_id="dolphin"]		border pixel 1
 # for_window [app_id="kitty"]		border pixel 1