diff --git a/lobby/src/test/kotlin/com/faforever/commons/lobby/LobbyClientTest.kt b/lobby/src/test/kotlin/com/faforever/commons/lobby/LobbyClientTest.kt
index 3b623ece..c255ecc1 100644
--- a/lobby/src/test/kotlin/com/faforever/commons/lobby/LobbyClientTest.kt
+++ b/lobby/src/test/kotlin/com/faforever/commons/lobby/LobbyClientTest.kt
@@ -47,7 +47,10 @@ class LobbyClientTest {
     }
   }
 
-  private val objectMapper: ObjectMapper = ObjectMapper().registerModule(KotlinModule()).registerModule(JavaTimeModule()).disable(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES).enable(DeserializationFeature.READ_UNKNOWN_ENUM_VALUES_USING_DEFAULT_VALUE);
+  private val objectMapper: ObjectMapper =
+    ObjectMapper().registerModule(KotlinModule.Builder().build()).registerModule(JavaTimeModule())
+      .disable(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES)
+      .enable(DeserializationFeature.READ_UNKNOWN_ENUM_VALUES_USING_DEFAULT_VALUE);
   private val token = "abc"
   private val serverReceivedSink = Sinks.many().unicast().onBackpressureBuffer<String>()
   private val serverMessagesReceived = serverReceivedSink.asFlux().publish().autoConnect()
diff --git a/lobby/src/test/kotlin/com/faforever/commons/lobby/ServerMessageTest.kt b/lobby/src/test/kotlin/com/faforever/commons/lobby/ServerMessageTest.kt
index 4ea53ea4..3394c139 100644
--- a/lobby/src/test/kotlin/com/faforever/commons/lobby/ServerMessageTest.kt
+++ b/lobby/src/test/kotlin/com/faforever/commons/lobby/ServerMessageTest.kt
@@ -17,7 +17,7 @@ class ServerMessageTest {
 
   companion object {
     val objectMapper: ObjectMapper = ObjectMapper()
-      .registerModule(KotlinModule())
+      .registerModule(KotlinModule.Builder().build())
       .registerModule(JavaTimeModule())
       .disable(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES)
   }