diff --git a/types/scene/output_layout.c b/types/scene/output_layout.c
index 42683f88..88185904 100644
--- a/types/scene/output_layout.c
+++ b/types/scene/output_layout.c
@@ -75,7 +75,9 @@ void wlr_scene_output_layout_add_output(struct wlr_scene_output_layout *sol,
 
 	struct wlr_scene_output_layout_output *solo;
 	wl_list_for_each(solo, &sol->outputs, link) {
-		assert(solo->scene_output != so);
+		if (solo->scene_output == so) {
+			return;
+		}
 	}
 
 	solo = calloc(1, sizeof(*solo));