diff --git a/src/zm_zone.cpp b/src/zm_zone.cpp
index 90c954d9e..e817f0908 100644
--- a/src/zm_zone.cpp
+++ b/src/zm_zone.cpp
@@ -51,6 +51,7 @@ void Zone::Setup( Monitor *p_monitor, int p_id, const char *p_label, ZoneType p_
 	Debug( 1, "Initialised zone %d/%s - %d - %dx%d - Rgb:%06x, CM:%d, MnAT:%d, MxAT:%d, MnAP:%d, MxAP:%d, FB:%dx%d, MnFP:%d, MxFP:%d, MnBS:%d, MxBS:%d, MnB:%d, MxB:%d, OF: %d, AF: %d", id, label, type, polygon.Width(), polygon.Height(), alarm_rgb, check_method, min_pixel_threshold, max_pixel_threshold, min_alarm_pixels, max_alarm_pixels, filter_box.X(), filter_box.Y(), min_filter_pixels, max_filter_pixels, min_blob_pixels, max_blob_pixels, min_blobs, max_blobs, overload_frames, extend_alarm_frames );
 
 	alarmed = false;
+	was_alarmed = false;
 	pixel_diff = 0;
 	alarm_pixels = 0;
 	alarm_filter_pixels = 0;
diff --git a/src/zm_zone.h b/src/zm_zone.h
index c431f88a0..266ffc753 100644
--- a/src/zm_zone.h
+++ b/src/zm_zone.h
@@ -126,14 +126,16 @@ public:
 	inline const Image *AlarmImage() const { return( image ); }
 	inline const Polygon &GetPolygon() const { return( polygon ); }
 	inline bool Alarmed() const { return( alarmed ); }
-	inline void SetAlarm() { alarmed = true; }
-	inline void ClearAlarm() { alarmed = false; }
+	inline bool WasAlarmed() const { return( was_alarmed ); }
+	inline void SetAlarm() { was_alarmed = alarmed; alarmed = true; }
+	inline void ClearAlarm() { was_alarmed = alarmed; alarmed = false; }
 	inline Coord GetAlarmCentre() const { return( alarm_centre ); }
 	inline unsigned int Score() const { return( score ); }
 
 	inline void ResetStats()
 	{
 		alarmed = false;
+		was_alarmed = false;
 		pixel_diff = 0;
 		alarm_pixels = 0;
 		alarm_filter_pixels = 0;