diff --git a/backend/x11/backend.c b/backend/x11/backend.c
index 768d00f79..089b38220 100644
--- a/backend/x11/backend.c
+++ b/backend/x11/backend.c
@@ -74,7 +74,7 @@ static void handle_x11_event(struct wlr_x11_backend *x11,
 		xcb_expose_event_t *ev = (xcb_expose_event_t *)event;
 		struct wlr_x11_output *output =
 			x11_output_from_window_id(x11, ev->window);
-		if (output != NULL) {
+		if (output != NULL && !output->wlr_output.frame_pending) {
 			wlr_output_send_frame(&output->wlr_output);
 		}
 		break;