diff --git a/src/main.c b/src/main.c
index 330d7ae..0cc194e 100644
--- a/src/main.c
+++ b/src/main.c
@@ -248,7 +248,7 @@ static void update_countdown_fsm(uint32_t time_ms)
 				if(m_countdown_off_time < 10 * ONE_MINUTE) {
 					m_countdown_off_time += 10 * ONE_MINUTE;
 				} else {
-					m_countdown_off_time *= 2;
+					m_countdown_off_time += countdown_time_remaining; // double remaining time
 				}
 
 				if((m_countdown_off_time - time_ms) > 10 * ONE_HOUR) {