diff --git a/build.sbt b/build.sbt
index d83950a..58223f2 100644
--- a/build.sbt
+++ b/build.sbt
@@ -25,7 +25,8 @@ lazy val `telegram-bot-delivery` = (project in file("."))
       circleGeneric,
       circleParser,
       circeAkkaHttp,
-      slibTelegram
+      slibTelegram,
+      logback
     ),
     dockerBaseImage := "openjdk:11",
     dockerExposedPorts := Seq(8443),
diff --git a/project/Dependencies.scala b/project/Dependencies.scala
index 32948b3..ed85b3e 100644
--- a/project/Dependencies.scala
+++ b/project/Dependencies.scala
@@ -12,6 +12,7 @@ object Dependencies {
     val akkaHttpCirceVersion = "1.31.0"
     val scalaTestVersion = "3.2.0-M4"
     val slibTelegramVersion = "0.1.0"
+    val logbackVersion = "1.2.3"
   }
 
   val akkaTyped = "com.typesafe.akka" %% "akka-actor-typed" % akkaVersion
@@ -28,4 +29,5 @@ object Dependencies {
   val circeAkkaHttp = "de.heikoseeberger" %% "akka-http-circe" % akkaHttpCirceVersion
   val slibTelegram = "eu.xeppaka" %% "slib-telegram" % slibTelegramVersion
   val scalaTest = "org.scalatest" %% "scalatest" % scalaTestVersion
+  val logback = "ch.qos.logback" % "logback-classic" % logbackVersion
 }
diff --git a/src/main/resources/application.conf b/src/main/resources/application.conf
index f8fb5ad..b484ba9 100644
--- a/src/main/resources/application.conf
+++ b/src/main/resources/application.conf
@@ -8,6 +8,8 @@ akka {
       plugin = "cassandra-journal"
     }
   }
+
+  actor.allow-java-serialization = on
 }
 
 cassandra-journal {
diff --git a/src/main/scala/eu/xeppaka/bot/CzechPostDeliveryCheck.scala b/src/main/scala/eu/xeppaka/bot/CzechPostDeliveryCheck.scala
index 84a7251..c570b29 100644
--- a/src/main/scala/eu/xeppaka/bot/CzechPostDeliveryCheck.scala
+++ b/src/main/scala/eu/xeppaka/bot/CzechPostDeliveryCheck.scala
@@ -106,9 +106,13 @@ object CzechPostDeliveryCheck {
   private case class ParcelHistoryRetrieved(parcelHistory: Entities.ParcelHistory) extends Command
   case class DeliveryStateChanged(state: String)
 
+  @SerialVersionUID(1L)
   case class ParcelAdded(parcelId: String, comment: String) extends Event
+  @SerialVersionUID(1L)
   case class ParcelRemoved(parcelId: String) extends Event
+  @SerialVersionUID(1L)
   case class ParcelHistoryStateAdded(parcelId: String, state: Entities.State) extends Event
+  @SerialVersionUID(1L)
   case class ParcelAttributesChanged(parcelId: String, attributes: Entities.Attributes) extends Event
 
   private val trustfulSslContext: SSLContext = {