diff --git a/app/src/main/java/org/tasks/backup/BackupContainer.kt b/app/src/main/java/org/tasks/backup/BackupContainer.kt
index 2685be3a1..3f0cc42c8 100644
--- a/app/src/main/java/org/tasks/backup/BackupContainer.kt
+++ b/app/src/main/java/org/tasks/backup/BackupContainer.kt
@@ -42,15 +42,14 @@ class BackupContainer(
     @Serializable
     class TaskBackup(
         val task: Task,
-        val alarms: List<Alarm>,
+        val alarms: List<Alarm>?,
         val geofences: List<Geofence>?,
-        val tags: List<Tag>,
-        val comments: List<UserActivity>,
+        val tags: List<Tag>?,
+        val comments: List<UserActivity>?,
         val attachments: List<Attachment>?,
         val caldavTasks: List<CaldavTask>?,
-        val vtodo: String? = null,
-        val google: List<GoogleTask> = emptyList(),
-    ) {
-        val locations: List<LegacyLocation> = emptyList()
-    }
+        val vtodo: String?,
+        val google: List<GoogleTask>? = null,
+        val locations: List<LegacyLocation>? = null,
+    )
 }
\ No newline at end of file
diff --git a/app/src/main/java/org/tasks/backup/TasksJsonImporter.kt b/app/src/main/java/org/tasks/backup/TasksJsonImporter.kt
index 4450cb10b..505de7583 100644
--- a/app/src/main/java/org/tasks/backup/TasksJsonImporter.kt
+++ b/app/src/main/java/org/tasks/backup/TasksJsonImporter.kt
@@ -92,7 +92,7 @@ class TasksJsonImporter @Inject constructor(
         try {
             val data = input.jsonObject["data"]!!
             val version = input.jsonObject["version"]!!.jsonPrimitive.int
-            val backupContainer = Json.decodeFromJsonElement<BackupContainer>(data)
+            val backupContainer = json.decodeFromJsonElement<BackupContainer>(data)
             backupContainer.tags?.forEach { tagData ->
                 findTagData(tagData)?.let {
                     return@forEach
@@ -203,7 +203,7 @@ class TasksJsonImporter @Inject constructor(
                 taskDao.createNew(task)
                 val taskId = task.id
                 val taskUuid = task.uuid
-                alarmDao.insert(backup.alarms.map { it.copy(task = taskId) })
+                backup.alarms?.map { it.copy(task = taskId) }?.let { alarmDao.insert(it) }
                 if (version < V12_4) {
                     task.defaultReminders(task.ringFlags)
                     alarmDao.insert(task.getDefaultAlarms())
@@ -218,14 +218,14 @@ class TasksJsonImporter @Inject constructor(
                     task.repeatFrom = task.recurrence.repeatFrom()
                     task.recurrence = task.recurrence.withoutFrom()
                 }
-                for (comment in backup.comments) {
+                backup.comments?.forEach { comment ->
                     comment.targetId = taskUuid
                     if (version < V6_4) {
                         comment.convertPictureUri()
                     }
                     userActivityDao.createNew(comment)
                 }
-                for (googleTask in backup.google) {
+                backup.google?.forEach { googleTask ->
                     caldavDao.insert(
                         CaldavTask(
                             task = taskId,
@@ -237,7 +237,7 @@ class TasksJsonImporter @Inject constructor(
                         )
                     )
                 }
-                for (location in backup.locations) {
+                backup.locations?.forEach { location ->
                     val place = Place(
                         longitude = location.longitude,
                         latitude = location.latitude,
@@ -256,8 +256,8 @@ class TasksJsonImporter @Inject constructor(
                         )
                     )
                 }
-                for (tag in backup.tags) {
-                    val tagData = findTagData(tag) ?: continue
+                backup.tags?.forEach tags@ { tag ->
+                    val tagData = findTagData(tag) ?: return@tags
                     tagDao.insert(
                         tag.copy(
                             task = taskId,
@@ -349,6 +349,7 @@ class TasksJsonImporter @Inject constructor(
         var skipCount = 0
     }
 
+    @Deprecated("For backup use only")
     @Serializable
     class LegacyLocation {
         var name: String? = null
@@ -363,6 +364,7 @@ class TasksJsonImporter @Inject constructor(
     }
 
     companion object {
+        private val json = Json { ignoreUnknownKeys = true}
         private val ignorePrefs = intArrayOf(
                 R.string.p_current_version,
                 R.string.p_backups_android_backup_last
diff --git a/data/src/commonMain/kotlin/org/tasks/data/entity/CaldavTask.kt b/data/src/commonMain/kotlin/org/tasks/data/entity/CaldavTask.kt
index dcb8965be..fad41be7a 100644
--- a/data/src/commonMain/kotlin/org/tasks/data/entity/CaldavTask.kt
+++ b/data/src/commonMain/kotlin/org/tasks/data/entity/CaldavTask.kt
@@ -4,6 +4,7 @@ import androidx.room.ColumnInfo
 import androidx.room.Entity
 import androidx.room.ForeignKey
 import androidx.room.PrimaryKey
+import kotlinx.serialization.SerialName
 import kotlinx.serialization.Serializable
 import kotlinx.serialization.Transient
 import org.tasks.data.UUIDHelper
@@ -35,6 +36,7 @@ data class CaldavTask(
     @ColumnInfo(name = "cd_remote_id")
     var remoteId: String? = UUIDHelper.newUUID(),
     @ColumnInfo(name = "cd_object")
+    @SerialName("object")
     var obj: String? = remoteId?.let { "$it.ics" },
     @ColumnInfo(name = "cd_etag")
     var etag: String? = null,