diff --git a/code/game/objects/structures/window.dm b/code/game/objects/structures/window.dm
index 17c32716b2b..dffc2ab09d6 100644
--- a/code/game/objects/structures/window.dm
+++ b/code/game/objects/structures/window.dm
@@ -305,9 +305,8 @@
 	air_update_turf(TRUE, FALSE)
 	add_fingerprint(user)
 
-/obj/structure/window/proc/on_painted(is_dark_color)
+/obj/structure/window/proc/on_painted(obj/structure/window/source, is_dark_color)
 	SIGNAL_HANDLER
-
 	if (is_dark_color && fulltile) //Opaque directional windows restrict vision even in directions they are not placed in, please don't do this
 		set_opacity(255)
 	else