diff --git a/matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/database/helper/ChunkEntityHelper.kt b/matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/database/helper/ChunkEntityHelper.kt
index 55ec1de925..5d7777480f 100644
--- a/matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/database/helper/ChunkEntityHelper.kt
+++ b/matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/database/helper/ChunkEntityHelper.kt
@@ -23,6 +23,7 @@ import io.realm.kotlin.createObject
 import org.matrix.android.sdk.api.session.events.model.content.EncryptedEventContent
 import org.matrix.android.sdk.api.session.events.model.toModel
 import org.matrix.android.sdk.api.session.room.model.RoomMemberContent
+import org.matrix.android.sdk.api.session.room.read.ReadService.Companion.THREAD_ID_MAIN
 import org.matrix.android.sdk.internal.crypto.model.SessionInfo
 import org.matrix.android.sdk.internal.database.mapper.asDomain
 import org.matrix.android.sdk.internal.database.model.ChunkEntity
@@ -136,17 +137,21 @@ private fun handleReadReceipts(realm: Realm, roomId: String, eventEntity: EventE
     val originServerTs = eventEntity.originServerTs
     if (originServerTs != null) {
         val timestampOfEvent = originServerTs.toDouble()
-        val readReceiptOfSender = ReadReceiptEntity.getOrCreate(realm, roomId = roomId, userId = senderId, threadId = eventEntity.rootThreadEventId)
-        // If the synced RR is older, update
-        if (timestampOfEvent > readReceiptOfSender.originServerTs) {
-            val previousReceiptsSummary = ReadReceiptsSummaryEntity.where(realm, eventId = readReceiptOfSender.eventId).findFirst()
-            rrDimber.i{"Handle outdated chunk RR $roomId / $senderId thread ${eventEntity.rootThreadEventId}: event ${readReceiptOfSender.eventId} -> ${eventEntity.eventId}"}
-            readReceiptOfSender.eventId = eventEntity.eventId
-            readReceiptOfSender.originServerTs = timestampOfEvent
-            previousReceiptsSummary?.readReceipts?.remove(readReceiptOfSender)
-            readReceiptsSummaryEntity.readReceipts.add(readReceiptOfSender)
-        } else {
-            rrDimber.i{"Handled chunk RR $roomId / $senderId thread ${eventEntity.rootThreadEventId}: keep ${readReceiptOfSender.eventId} (not ${eventEntity.eventId})"}
+        // null receipts also update the main receipt
+        val receiptDestination = eventEntity.rootThreadEventId ?: THREAD_ID_MAIN
+        setOf(receiptDestination, eventEntity.rootThreadEventId).distinct().forEach { rootThreadEventId ->
+            val readReceiptOfSender = ReadReceiptEntity.getOrCreate(realm, roomId = roomId, userId = senderId, threadId = rootThreadEventId)
+            // If the synced RR is older, update
+            if (timestampOfEvent > readReceiptOfSender.originServerTs) {
+                val previousReceiptsSummary = ReadReceiptsSummaryEntity.where(realm, eventId = readReceiptOfSender.eventId).findFirst()
+                rrDimber.i { "Handle outdated chunk RR $roomId / $senderId thread $rootThreadEventId(${eventEntity.rootThreadEventId}): event ${readReceiptOfSender.eventId} -> ${eventEntity.eventId}" }
+                readReceiptOfSender.eventId = eventEntity.eventId
+                readReceiptOfSender.originServerTs = timestampOfEvent
+                previousReceiptsSummary?.readReceipts?.remove(readReceiptOfSender)
+                readReceiptsSummaryEntity.readReceipts.add(readReceiptOfSender)
+            } else {
+                rrDimber.i { "Handled chunk RR $roomId / $senderId thread $rootThreadEventId(${eventEntity.rootThreadEventId}): keep ${readReceiptOfSender.eventId} (not ${eventEntity.eventId})" }
+            }
         }
     }
     return readReceiptsSummaryEntity
diff --git a/matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/session/sync/handler/room/ReadReceiptHandler.kt b/matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/session/sync/handler/room/ReadReceiptHandler.kt
index 40dce190c5..64343689ab 100644
--- a/matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/session/sync/handler/room/ReadReceiptHandler.kt
+++ b/matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/session/sync/handler/room/ReadReceiptHandler.kt
@@ -20,6 +20,7 @@ import de.spiritcroc.matrixsdk.util.DbgUtil
 import de.spiritcroc.matrixsdk.util.Dimber
 import io.realm.Realm
 import org.matrix.android.sdk.api.session.events.model.EventType
+import org.matrix.android.sdk.api.session.room.read.ReadService
 import org.matrix.android.sdk.internal.database.model.ReadReceiptEntity
 import org.matrix.android.sdk.internal.database.model.ReadReceiptsSummaryEntity
 import org.matrix.android.sdk.internal.database.query.createUnmanaged
@@ -145,19 +146,22 @@ internal class ReadReceiptHandler @Inject constructor(
 
             for ((userId, paramsDict) in userIdsDict) {
                 val ts = paramsDict[TIMESTAMP_KEY] as? Double ?: 0.0
-                val threadId = paramsDict[THREAD_ID_KEY] as String?
-                val receiptEntity = ReadReceiptEntity.getOrCreate(realm, roomId, userId, threadId)
-                // ensure new ts is superior to the previous one
-                if (ts > receiptEntity.originServerTs) {
-                    rrDimber.i{"Handle outdated sync RR $roomId / $userId thread $threadId: event ${receiptEntity.eventId} -> $eventId"}
-                    ReadReceiptsSummaryEntity.where(realm, receiptEntity.eventId).findFirst()?.also {
-                        it.readReceipts.remove(receiptEntity)
+                val syncedThreadId = paramsDict[THREAD_ID_KEY] as String?
+                val receiptDestination = syncedThreadId ?: ReadService.THREAD_ID_MAIN
+                setOf(receiptDestination, syncedThreadId).distinct().forEach { threadId ->
+                    val receiptEntity = ReadReceiptEntity.getOrCreate(realm, roomId, userId, threadId)
+                    // ensure new ts is superior to the previous one
+                    if (ts > receiptEntity.originServerTs) {
+                        rrDimber.i { "Handle outdated sync RR $roomId / $userId thread $threadId($syncedThreadId): event ${receiptEntity.eventId} -> $eventId" }
+                        ReadReceiptsSummaryEntity.where(realm, receiptEntity.eventId).findFirst()?.also {
+                            it.readReceipts.remove(receiptEntity)
+                        }
+                        receiptEntity.eventId = eventId
+                        receiptEntity.originServerTs = ts
+                        readReceiptsSummary.readReceipts.add(receiptEntity)
+                    } else {
+                        rrDimber.i { "Handle keep sync RR $roomId / $userId thread $threadId($syncedThreadId): event ${receiptEntity.eventId} (not $eventId)" }
                     }
-                    receiptEntity.eventId = eventId
-                    receiptEntity.originServerTs = ts
-                    readReceiptsSummary.readReceipts.add(receiptEntity)
-                } else {
-                    rrDimber.i{"Handle keep sync RR $roomId / $userId thread $threadId: event ${receiptEntity.eventId} (not $eventId)"}
                 }
             }
         }
diff --git a/vector/src/main/java/im/vector/app/features/home/room/detail/timeline/TimelineEventController.kt b/vector/src/main/java/im/vector/app/features/home/room/detail/timeline/TimelineEventController.kt
index efa36c8247..701059dce4 100644
--- a/vector/src/main/java/im/vector/app/features/home/room/detail/timeline/TimelineEventController.kt
+++ b/vector/src/main/java/im/vector/app/features/home/room/detail/timeline/TimelineEventController.kt
@@ -628,7 +628,7 @@ class TimelineEventController @Inject constructor(
         return if (partialState.isFromThreadTimeline()) {
             this.threadId == partialState.rootThreadEventId
         } else {
-            this.threadId == null || this.threadId == ReadService.THREAD_ID_MAIN
+            this.threadId == ReadService.THREAD_ID_MAIN
         }
     }