diff --git a/libraries/matrix/impl/src/main/kotlin/io/element/android/libraries/matrix/impl/room/JoinedRustRoom.kt b/libraries/matrix/impl/src/main/kotlin/io/element/android/libraries/matrix/impl/room/JoinedRustRoom.kt
index 17a3910c98..3be63f4f97 100644
--- a/libraries/matrix/impl/src/main/kotlin/io/element/android/libraries/matrix/impl/room/JoinedRustRoom.kt
+++ b/libraries/matrix/impl/src/main/kotlin/io/element/android/libraries/matrix/impl/room/JoinedRustRoom.kt
@@ -158,6 +158,7 @@ class JoinedRustRoom(
         inner = innerRoom.threadListService(),
         contentMapper = TimelineEventContentMapper(),
         roomCoroutineScope = roomCoroutineScope,
+        roomDispatcher = roomDispatcher,
     )
 
     override val syncUpdateFlow = flow {
diff --git a/libraries/matrix/impl/src/main/kotlin/io/element/android/libraries/matrix/impl/room/threads/RustThreadsListService.kt b/libraries/matrix/impl/src/main/kotlin/io/element/android/libraries/matrix/impl/room/threads/RustThreadsListService.kt
index a74c5bc378..98248b183b 100644
--- a/libraries/matrix/impl/src/main/kotlin/io/element/android/libraries/matrix/impl/room/threads/RustThreadsListService.kt
+++ b/libraries/matrix/impl/src/main/kotlin/io/element/android/libraries/matrix/impl/room/threads/RustThreadsListService.kt
@@ -17,10 +17,12 @@ import io.element.android.libraries.matrix.api.room.threads.ThreadsListService
 import io.element.android.libraries.matrix.impl.timeline.item.event.TimelineEventContentMapper
 import io.element.android.libraries.matrix.impl.timeline.item.event.map
 import io.element.android.libraries.matrix.impl.util.mxCallbackFlow
+import kotlinx.coroutines.CoroutineDispatcher
 import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.Job
 import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.flowOn
 import kotlinx.coroutines.flow.launchIn
 import kotlinx.coroutines.flow.onEach
 import kotlinx.coroutines.flow.onStart
@@ -33,6 +35,7 @@ import org.matrix.rustcomponents.sdk.ThreadListService as InnerThreadListService
 class RustThreadsListService(
     private val inner: InnerThreadListService,
     private val roomCoroutineScope: CoroutineScope,
+    private val roomDispatcher: CoroutineDispatcher,
     private val contentMapper: TimelineEventContentMapper = TimelineEventContentMapper(),
 ) : ThreadsListService {
     private var itemSubscriptionJob: Job? = null
@@ -63,6 +66,8 @@ class RustThreadsListService(
                 updated.apply(diff, contentMapper)
                 items.value = updated
             }
+            // Fetching and mapping the items can be costly, do not do it on the main thread
+            .flowOn(roomDispatcher)
             .launchIn(roomCoroutineScope)
     }
 
diff --git a/libraries/matrix/impl/src/test/kotlin/io/element/android/libraries/matrix/impl/room/threads/RustThreadsListServiceTest.kt b/libraries/matrix/impl/src/test/kotlin/io/element/android/libraries/matrix/impl/room/threads/RustThreadsListServiceTest.kt
index 0fc9ad0603..fd9f311b95 100644
--- a/libraries/matrix/impl/src/test/kotlin/io/element/android/libraries/matrix/impl/room/threads/RustThreadsListServiceTest.kt
+++ b/libraries/matrix/impl/src/test/kotlin/io/element/android/libraries/matrix/impl/room/threads/RustThreadsListServiceTest.kt
@@ -18,6 +18,7 @@ import io.element.android.libraries.matrix.test.A_TIMESTAMP
 import io.element.android.libraries.matrix.test.A_USER_ID
 import io.element.android.tests.testutils.lambda.lambdaRecorder
 import kotlinx.coroutines.ExperimentalCoroutinesApi
+import kotlinx.coroutines.test.StandardTestDispatcher
 import kotlinx.coroutines.test.TestScope
 import kotlinx.coroutines.test.runCurrent
 import kotlinx.coroutines.test.runTest
@@ -122,6 +123,7 @@ class RustThreadsListServiceTest {
     ) = RustThreadsListService(
         inner = inner,
         roomCoroutineScope = backgroundScope,
+        roomDispatcher = StandardTestDispatcher(testScheduler),
     )
 
     private fun aRustThreadListUpdate() = ThreadListUpdate.Append(