diff --git a/api/android-sdk-core.api b/api/android-sdk-core.api
index df5319a..69a64a5 100644
--- a/api/android-sdk-core.api
+++ b/api/android-sdk-core.api
@@ -259,6 +259,7 @@ public abstract class com.mapconductor.core.controller.BaseMapViewController imp
   public final void setMapClickListener(kotlin.jvm.functions.Function1<? super com.mapconductor.core.features.GeoPoint, kotlin.Unit>);
   public final void setMapLongClickListener(kotlin.jvm.functions.Function1<? super com.mapconductor.core.features.GeoPoint, kotlin.Unit>);
   public void registerOverlayController(com.mapconductor.core.controller.OverlayControllerInterface<?, ?>);
+  protected final java.lang.Object clearStrategyMarkerControllers(kotlin.coroutines.Continuation<? super kotlin.Unit>);
   protected java.util.List<com.mapconductor.core.controller.OverlayKind> getOverlayCascadeOrder();
   protected boolean dispatchMarkerTap(com.mapconductor.core.features.GeoPointInterface);
   public final boolean dispatchOverlayTap(com.mapconductor.core.features.GeoPointInterface);
diff --git a/src/main/java/com/mapconductor/core/controller/BaseMapViewController.kt b/src/main/java/com/mapconductor/core/controller/BaseMapViewController.kt
index c989e3a..02ef930 100644
--- a/src/main/java/com/mapconductor/core/controller/BaseMapViewController.kt
+++ b/src/main/java/com/mapconductor/core/controller/BaseMapViewController.kt
@@ -19,6 +19,7 @@ import com.mapconductor.core.marker.MarkerAnimationOverlayHost
 import com.mapconductor.core.marker.MarkerCapableInterface
 import com.mapconductor.core.marker.MarkerState
 import com.mapconductor.core.marker.OnMarkerEventHandler
+import com.mapconductor.core.marker.StrategyMarkerController
 import com.mapconductor.core.polygon.OnPolygonEventHandler
 import com.mapconductor.core.polygon.PolygonCapableInterface
 import com.mapconductor.core.polygon.PolygonState
@@ -158,6 +159,21 @@ abstract class BaseMapViewController :
         }
     }
 
+    /**
+     * 登録されている [StrategyMarkerController]（クラスタリングなどの Strategy で描くマーカー）を
+     * すべて clear する。各プロバイダの `clearOverlays()` から呼ぶ。
+     *
+     * Strategy のコントローラはプロバイダが持つものではなく、拡張モジュール
+     * （android-marker-clustering の MarkerRenderingGroup など）が
+     * [registerOverlayController] で登録していくもの。プロバイダの `clearOverlays()` は
+     * 自分のフィールドのコントローラしか知らないので、ここで登録簿から拾う。
+     *
+     * 他の種類（ヒートマップのようにカメラだけ購読するもの）は消さない。
+     */
+    protected suspend fun clearStrategyMarkerControllers() {
+        overlayControllers.filterIsInstance<StrategyMarkerController<*>>().forEach { it.clear() }
+    }
+
     // ── タップのカスケード ──────────────────────────────────────────────
     //
     // marker → circle → groundImage → polyline → polygon → map の一本道。
diff --git a/src/test/java/com/mapconductor/core/controller/ClearStrategyMarkerControllersTest.kt b/src/test/java/com/mapconductor/core/controller/ClearStrategyMarkerControllersTest.kt
new file mode 100644
index 0000000..f20fb69
--- /dev/null
+++ b/src/test/java/com/mapconductor/core/controller/ClearStrategyMarkerControllersTest.kt
@@ -0,0 +1,167 @@
+package com.mapconductor.core.controller
+
+import com.mapconductor.core.features.GeoPoint
+import com.mapconductor.core.features.GeoPointInterface
+import com.mapconductor.core.features.GeoRectBounds
+import com.mapconductor.core.map.MapCameraPosition
+import com.mapconductor.core.map.MapViewHolderInterface
+import com.mapconductor.core.map.VisibleRegion
+import com.mapconductor.core.marker.MarkerEntity
+import com.mapconductor.core.marker.MarkerEntityInterface
+import com.mapconductor.core.marker.MarkerManager
+import com.mapconductor.core.marker.MarkerOverlayRendererInterface
+import com.mapconductor.core.marker.MarkerRenderingStrategyInterface
+import com.mapconductor.core.marker.MarkerState
+import com.mapconductor.core.marker.OnMarkerEventHandler
+import com.mapconductor.core.marker.StrategyMarkerController
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.test.runTest
+import org.junit.Assert.assertEquals
+import org.junit.Test
+
+/**
+ * `clearOverlays()` が、拡張モジュールが [BaseMapViewController.registerOverlayController] で
+ * 登録した [StrategyMarkerController]（クラスタリングなど）も消すこと。
+ *
+ * プロバイダの `clearOverlays()` は自分のフィールドのコントローラしか clear しておらず、
+ * Strategy で描いたマーカーは clearOverlays() の後も地図に残っていた。
+ */
+class ClearStrategyMarkerControllersTest {
+    private val bounds = GeoRectBounds(GeoPoint(34.0, 138.0), GeoPoint(36.0, 140.0))
+    private val camera =
+        MapCameraPosition(
+            position = GeoPoint(35.0, 139.0),
+            zoom = 10.0,
+            visibleRegion = VisibleRegion(bounds, null, null, null, null),
+        )
+
+    /** GL 系の描画担当: onPostProcess で manager の全部を描き直す。 */
+    private class GlRenderer(
+        private val manager: MarkerManager<String>,
+    ) : MarkerOverlayRendererInterface<String> {
+        var drawn: List<String> = emptyList()
+        override var animateStartListener: OnMarkerEventHandler? = null
+        override var animateEndListener: OnMarkerEventHandler? = null
+        override val holder: MapViewHolderInterface<*, *>
+            get() = throw UnsupportedOperationException("not used")
+
+        override suspend fun onAdd(data: List<MarkerOverlayRendererInterface.AddParamsInterface>) = data.map { it.state.id }
+
+        override suspend fun onChange(data: List<MarkerOverlayRendererInterface.ChangeParamsInterface<String>>) =
+            data.map { it.current.state.id }
+
+        override suspend fun onRemove(data: List<MarkerEntityInterface<String>>) = Unit
+
+        override suspend fun onAnimate(entity: MarkerEntityInterface<String>) = Unit
+
+        override suspend fun onPostProcess() {
+            drawn = manager.allEntities().map { it.state.id }.sorted()
+        }
+    }
+
+    private class DrawAllStrategy : MarkerRenderingStrategyInterface<String> {
+        override val markerManager: MarkerManager<String> = MarkerManager.defaultManager()
+
+        override fun clear() = markerManager.clear()
+
+        override suspend fun onUpdate(
+            state: MarkerState,
+            viewport: GeoRectBounds,
+            renderer: MarkerOverlayRendererInterface<String>,
+        ): Boolean = true
+
+        override suspend fun onAdd(
+            data: List<MarkerState>,
+            viewport: GeoRectBounds,
+            renderer: MarkerOverlayRendererInterface<String>,
+        ): Boolean {
+            data.forEach { markerManager.registerEntity(MarkerEntity(marker = it.id, state = it, isRendered = true)) }
+            renderer.onPostProcess()
+            return true
+        }
+
+        override suspend fun onCameraChanged(
+            cameraPosition: MapCameraPosition,
+            renderer: MarkerOverlayRendererInterface<String>,
+        ) = Unit
+    }
+
+    /** カメラだけ購読する拡張（android-heatmap のような）。clearOverlays で触られてはいけない。 */
+    private class CameraOnlyController : OverlayControllerInterface<Unit, Unit> {
+        var cleared = 0
+        override val zIndex = 0
+
+        override suspend fun add(data: List<Unit>) = Unit
+
+        override suspend fun update(state: Unit) = Unit
+
+        override suspend fun clear() {
+            cleared++
+        }
+
+        override fun find(position: GeoPointInterface): Unit? = null
+
+        override fun destroy() = Unit
+    }
+
+    /** プロバイダの clearOverlays() と同じ形: 自分のコントローラを消してから共通部分を呼ぶ。 */
+    private class Driver : BaseMapViewController() {
+        override val holder get() = throw UnsupportedOperationException()
+        override val defaultCoroutine = CoroutineScope(Dispatchers.Unconfined)
+        override val mainCoroutine = defaultCoroutine
+
+        override fun moveCamera(position: MapCameraPosition) = Unit
+
+        override fun animateCamera(
+            position: MapCameraPosition,
+            duration: Long,
+        ) = Unit
+
+        override fun fitBounds(
+            bounds: GeoRectBounds,
+            padding: Int,
+        ) = Unit
+
+        override suspend fun clearOverlays() {
+            clearStrategyMarkerControllers()
+        }
+    }
+
+    private fun markers() =
+        listOf(
+            MarkerState(position = GeoPoint(35.0, 139.0), id = "m1"),
+            MarkerState(position = GeoPoint(35.1, 139.1), id = "m2"),
+        )
+
+    @Test
+    fun `clearOverlays は登録された Strategy のマーカーを消し、他の登録物には触らない`() =
+        runTest {
+            val driver = Driver()
+            val groups =
+                (0..1).map {
+                    val strategy = DrawAllStrategy()
+                    val renderer = GlRenderer(strategy.markerManager)
+                    val controller = StrategyMarkerController(strategy, renderer)
+                    driver.registerOverlayController(controller)
+                    controller.onCameraChanged(camera)
+                    controller.add(markers())
+                    Triple(strategy, renderer, controller)
+                }
+            val other = CameraOnlyController()
+            driver.registerOverlayController(other)
+            groups.forEach { assertEquals(listOf("m1", "m2"), it.second.drawn) }
+
+            driver.clearOverlays()
+
+            groups.forEach { (strategy, renderer, _) ->
+                assertEquals(emptyList<String>(), renderer.drawn)
+                assertEquals(0, strategy.markerManager.allEntities().size)
+            }
+            assertEquals(0, other.cleared)
+
+            // 送り直せばまた描かれる。
+            groups.forEach { it.third.add(markers()) }
+            groups.forEach { assertEquals(listOf("m1", "m2"), it.second.drawn) }
+        }
+}