diff --git a/src/main/java/com/mapconductor/longdo/LongdoMapViewController.kt b/src/main/java/com/mapconductor/longdo/LongdoMapViewController.kt
index 2161b8d..cdf631e 100644
--- a/src/main/java/com/mapconductor/longdo/LongdoMapViewController.kt
+++ b/src/main/java/com/mapconductor/longdo/LongdoMapViewController.kt
@@ -428,6 +428,8 @@ class LongdoMapViewController(
         circleController.clear()
         removeMarkerTileRaster()
         markerTileRenderer?.clear()
+        // 拡張モジュール（クラスタリングなど）が登録した Strategy のマーカーも消す。
+        clearStrategyMarkerControllers()
     }
 
     internal var appliedUISettings: MapUISettings = MapUISettings.Default