diff --git a/vector/src/main/java/im/vector/riotredesign/features/home/HomeDetailViewModel.kt b/vector/src/main/java/im/vector/riotredesign/features/home/HomeDetailViewModel.kt
index 9e36dfc162..81a8f790fa 100644
--- a/vector/src/main/java/im/vector/riotredesign/features/home/HomeDetailViewModel.kt
+++ b/vector/src/main/java/im/vector/riotredesign/features/home/HomeDetailViewModel.kt
@@ -52,7 +52,7 @@ class HomeDetailViewModel(initialState: HomeDetailViewState,
                                 .filter { it.isDirect }
                                 .map { it.notificationCount }
                                 .takeIf { it.isNotEmpty() }
-                                ?.reduce { acc, i -> acc + i }
+                                ?.sumBy { i -> i }
                                 ?: 0
                         val peopleHasHighlight = summaries
                                 .filter { it.isDirect }
@@ -62,7 +62,7 @@ class HomeDetailViewModel(initialState: HomeDetailViewState,
                                 .filter { !it.isDirect }
                                 .map { it.notificationCount }
                                 .takeIf { it.isNotEmpty() }
-                                ?.reduce { acc, i -> acc + i }
+                                ?.sumBy { i -> i }
                                 ?: 0
                         val roomsHasHighlight = summaries
                                 .filter { !it.isDirect }
diff --git a/vector/src/main/java/im/vector/riotredesign/features/home/room/list/RoomSummaryController.kt b/vector/src/main/java/im/vector/riotredesign/features/home/room/list/RoomSummaryController.kt
index 9d8e555f07..eafcb7dd4e 100644
--- a/vector/src/main/java/im/vector/riotredesign/features/home/room/list/RoomSummaryController.kt
+++ b/vector/src/main/java/im/vector/riotredesign/features/home/room/list/RoomSummaryController.kt
@@ -64,7 +64,7 @@ class RoomSummaryController(private val stringProvider: StringProvider,
         val unreadCount = if (summaries.isEmpty()) {
             0
         } else {
-            summaries.map { it.notificationCount }.reduce { acc, i -> acc + i }
+            summaries.map { it.notificationCount }.sumBy { i -> i }
         }
         val showHighlighted = summaries.any { it.highlightCount > 0 }
         roomCategoryItem {