diff --git a/matrix-sdk-android/src/main/java/im/vector/matrix/android/api/util/CancelableBag.kt b/matrix-sdk-android/src/main/java/im/vector/matrix/android/api/util/CancelableBag.kt
index 95fdc3de24..f5689b4d13 100644
--- a/matrix-sdk-android/src/main/java/im/vector/matrix/android/api/util/CancelableBag.kt
+++ b/matrix-sdk-android/src/main/java/im/vector/matrix/android/api/util/CancelableBag.kt
@@ -16,20 +16,8 @@
 
 package im.vector.matrix.android.api.util
 
-class CancelableBag : Cancelable {
-
-    private val cancelableList = ArrayList<Cancelable>()
-
-    fun add(cancelable: Cancelable) {
-        cancelableList.add(cancelable)
-    }
-
+class CancelableBag : Cancelable, MutableList<Cancelable> by ArrayList() {
     override fun cancel() {
-        cancelableList.forEach { it.cancel() }
+        forEach { it.cancel() }
     }
-
 }
-
-fun Cancelable.addTo(cancelables: CancelableBag) {
-    cancelables.add(this)
-}
\ No newline at end of file
diff --git a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/session/room/send/DefaultSendService.kt b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/session/room/send/DefaultSendService.kt
index fc4bf8c468..162b9d3a34 100644
--- a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/session/room/send/DefaultSendService.kt
+++ b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/session/room/send/DefaultSendService.kt
@@ -26,7 +26,6 @@ import im.vector.matrix.android.api.session.events.model.Event
 import im.vector.matrix.android.api.session.room.send.SendService
 import im.vector.matrix.android.api.util.Cancelable
 import im.vector.matrix.android.api.util.CancelableBag
-import im.vector.matrix.android.api.util.addTo
 import im.vector.matrix.android.internal.session.content.UploadContentWorker
 import im.vector.matrix.android.internal.session.room.timeline.TimelineSendEventWorkCommon
 import im.vector.matrix.android.internal.util.CancelableWork
@@ -82,11 +81,9 @@ internal class DefaultSendService @Inject constructor(private val context: Conte
     }
 
     override fun sendMedias(attachments: List<ContentAttachmentData>): Cancelable {
-        val cancelableBag = CancelableBag()
-        attachments.forEach {
-            sendMedia(it).addTo(cancelableBag)
+        return attachments.mapTo(CancelableBag()) {
+            sendMedia(it)
         }
-        return cancelableBag
     }
 
     override fun redactEvent(event: Event, reason: String?): Cancelable {
diff --git a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/session/room/timeline/DefaultTimeline.kt b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/session/room/timeline/DefaultTimeline.kt
index 8f5c62cdcb..327ea24103 100644
--- a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/session/room/timeline/DefaultTimeline.kt
+++ b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/session/room/timeline/DefaultTimeline.kt
@@ -23,7 +23,6 @@ import im.vector.matrix.android.api.session.events.model.toModel
 import im.vector.matrix.android.api.session.room.timeline.Timeline
 import im.vector.matrix.android.api.session.room.timeline.TimelineEvent
 import im.vector.matrix.android.api.util.CancelableBag
-import im.vector.matrix.android.api.util.addTo
 import im.vector.matrix.android.internal.crypto.NewSessionListener
 import im.vector.matrix.android.internal.crypto.model.event.EncryptedEventContent
 import im.vector.matrix.android.internal.database.mapper.asDomain
@@ -396,7 +395,7 @@ internal class DefaultTimeline(
                                            limit = limit)
 
         Timber.v("Should fetch $limit items $direction")
-        paginationTask.configureWith(params)
+        cancelableBag += paginationTask.configureWith(params)
                 .enableRetry()
                 .dispatchTo(object : MatrixCallback<TokenChunkEventPersistor.Result> {
                     override fun onSuccess(data: TokenChunkEventPersistor.Result) {
@@ -415,7 +414,6 @@ internal class DefaultTimeline(
                     }
                 })
                 .executeBy(taskExecutor)
-                .addTo(cancelableBag)
     }
 
     /**