diff --git a/modules/factorio-events-processor/src/main/kotlin/dev/adamko/factorioevents/processor/model/FactorioServerLogRecord.kt b/modules/factorio-events-processor/src/main/kotlin/dev/adamko/factorioevents/processor/model/FactorioServerLogRecord.kt
index c8a8182..7ec2a35 100644
--- a/modules/factorio-events-processor/src/main/kotlin/dev/adamko/factorioevents/processor/model/FactorioServerLogRecord.kt
+++ b/modules/factorio-events-processor/src/main/kotlin/dev/adamko/factorioevents/processor/model/FactorioServerLogRecord.kt
@@ -9,8 +9,6 @@ import java.math.BigInteger
 import kotlin.reflect.KClass
 
 
-
-
 data class FactorioServerLogRecord<DataType : FactorioObjectData>(
   @JsonProperty("mod_version")
   val modVersion: String,
@@ -22,12 +20,11 @@ data class FactorioServerLogRecord<DataType : FactorioObjectData>(
   val data: DataType,
 )
 
-
 @JsonTypeInfo(
   use = JsonTypeInfo.Id.NAME,
-  include = JsonTypeInfo.As.PROPERTY,
+  include = JsonTypeInfo.As.EXISTING_PROPERTY,
   property = "object_name",
-  defaultImpl = Void::class, // equivalent to null
+  defaultImpl = UnknownFactorioObject::class,
   visible = true,
 )
 sealed class FactorioObjectData(
@@ -35,6 +32,8 @@ sealed class FactorioObjectData(
   val objectName: String
 )
 
+object UnknownFactorioObject : FactorioObjectData("unknown")
+
 @JsonTypeName("LuaSurface")
 class LuaSurfaceData(
   @JsonProperty("name")