diff --git a/app/src/main/java/com/infomaniak/mail/data/cache/mailboxContent/ImpactedFolders.kt b/app/src/main/java/com/infomaniak/mail/data/cache/mailboxContent/ImpactedFolders.kt
index e5a433d04c..fedf160cf9 100644
--- a/app/src/main/java/com/infomaniak/mail/data/cache/mailboxContent/ImpactedFolders.kt
+++ b/app/src/main/java/com/infomaniak/mail/data/cache/mailboxContent/ImpactedFolders.kt
@@ -42,7 +42,7 @@ data class ImpactedFolders(
      */
     fun getFolderIds(realm: TypedRealm): Set<String> {
         folderRoles.forEach { folderRole ->
-            FolderController.getFolder(folderRole, realm)?.let { folderIds.add(it.id) }
+            FolderController.getFolder(folderRole, realm)?.id?.let(folderIds::add)
         }
 
         return folderIds