diff --git a/wdmtg.c b/wdmtg.c
index 289b48d..b2a9d0b 100644
--- a/wdmtg.c
+++ b/wdmtg.c
@@ -540,11 +540,16 @@ generator_init(void)
 	g_free(subpath);
 	g_key_file_free(kf);
 
+	// Write a start marker so that we can reliably detect interruptions
+	struct event *event = g_slice_new0(struct event);
+	event->timestamp = -1;
+	g_async_queue_push(g.queue, event);
+
+	update_current_window();
+
 	gint64 timeout_ms = timeout * 1000;
 	gen.idle_timeout.hi = timeout_ms >> 32;
 	gen.idle_timeout.lo = timeout_ms;
-
-	update_current_window();
 	set_idle_alarm(&gen.idle_alarm_inactive,
 		XCB_SYNC_TESTTYPE_POSITIVE_COMPARISON, gen.idle_timeout);