diff --git a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/session/content/UploadContentWorker.kt b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/session/content/UploadContentWorker.kt
index 90d15cc3b2..5a8688ee6a 100644
--- a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/session/content/UploadContentWorker.kt
+++ b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/session/content/UploadContentWorker.kt
@@ -48,7 +48,7 @@ internal class UploadContentWorker(context: Context, params: WorkerParameters) :
             val event: Event,
             val attachment: ContentAttachmentData,
             val isRoomEncrypted: Boolean,
-            override var lastFailureMessage: String? = null
+            override val lastFailureMessage: String? = null
     ) : SessionWorkerParams
 
     @Inject lateinit var fileUploader: FileUploader
diff --git a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/session/group/GetGroupDataWorker.kt b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/session/group/GetGroupDataWorker.kt
index a619b83a4d..081739cbbb 100644
--- a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/session/group/GetGroupDataWorker.kt
+++ b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/session/group/GetGroupDataWorker.kt
@@ -32,7 +32,7 @@ internal class GetGroupDataWorker(context: Context, params: WorkerParameters) :
     internal data class Params(
             override val userId: String,
             val groupIds: List<String>,
-            override var lastFailureMessage: String? = null
+            override val lastFailureMessage: String? = null
     ) : SessionWorkerParams
 
     @Inject lateinit var getGroupDataTask: GetGroupDataTask
diff --git a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/session/room/relation/SendRelationWorker.kt b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/session/room/relation/SendRelationWorker.kt
index a04c7b3ed6..81a888eea4 100644
--- a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/session/room/relation/SendRelationWorker.kt
+++ b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/session/room/relation/SendRelationWorker.kt
@@ -40,7 +40,7 @@ internal class SendRelationWorker(context: Context, params: WorkerParameters) :
             val roomId: String,
             val event: Event,
             val relationType: String? = null,
-            override var lastFailureMessage: String?
+            override val lastFailureMessage: String?
     ) : SessionWorkerParams
 
     @Inject lateinit var roomAPI: RoomAPI
diff --git a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/session/room/send/EncryptEventWorker.kt b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/session/room/send/EncryptEventWorker.kt
index 44046a1dea..118fa7ccb5 100644
--- a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/session/room/send/EncryptEventWorker.kt
+++ b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/session/room/send/EncryptEventWorker.kt
@@ -42,7 +42,7 @@ internal class EncryptEventWorker(context: Context, params: WorkerParameters)
             val event: Event,
             /**Do not encrypt these keys, keep them as is in encrypted content (e.g. m.relates_to)*/
             val keepKeys: List<String>? = null,
-            override var lastFailureMessage: String? = null
+            override val lastFailureMessage: String? = null
     ) : SessionWorkerParams
 
     @Inject lateinit var crypto: CryptoService
diff --git a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/session/room/send/RedactEventWorker.kt b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/session/room/send/RedactEventWorker.kt
index 38e0e23b6e..5acc16e19e 100644
--- a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/session/room/send/RedactEventWorker.kt
+++ b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/session/room/send/RedactEventWorker.kt
@@ -36,7 +36,7 @@ internal class RedactEventWorker(context: Context, params: WorkerParameters) : C
             val roomId: String,
             val eventId: String,
             val reason: String?,
-            override var lastFailureMessage: String? = null
+            override val lastFailureMessage: String? = null
     ) : SessionWorkerParams
 
     @Inject lateinit var roomAPI: RoomAPI
diff --git a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/session/room/send/SendEventWorker.kt b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/session/room/send/SendEventWorker.kt
index 315ea4574d..05cd56e38f 100644
--- a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/session/room/send/SendEventWorker.kt
+++ b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/session/room/send/SendEventWorker.kt
@@ -39,7 +39,7 @@ internal class SendEventWorker constructor(context: Context, params: WorkerParam
             override val userId: String,
             val roomId: String,
             val event: Event,
-            override var lastFailureMessage: String? = null
+            override val lastFailureMessage: String? = null
     ) : SessionWorkerParams
 
     @Inject lateinit var localEchoUpdater: LocalEchoUpdater
diff --git a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/worker/SessionWorkerParams.kt b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/worker/SessionWorkerParams.kt
index 99fe3142dc..0c53a3ef0b 100644
--- a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/worker/SessionWorkerParams.kt
+++ b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/worker/SessionWorkerParams.kt
@@ -20,5 +20,5 @@ interface SessionWorkerParams {
     val userId: String
 
     // Null is no error occurs. When chaining Workers, first step is to check that there is no lastFailureMessage from the previous workers
-    var lastFailureMessage: String?
+    val lastFailureMessage: String?
 }