diff --git a/src/commonMain/kotlin/com/github/quillraven/fleks/entity.kt b/src/commonMain/kotlin/com/github/quillraven/fleks/entity.kt
index 8be7aad..052fc62 100644
--- a/src/commonMain/kotlin/com/github/quillraven/fleks/entity.kt
+++ b/src/commonMain/kotlin/com/github/quillraven/fleks/entity.kt
@@ -7,9 +7,8 @@ import kotlin.jvm.JvmInline
 /**
  * An entity of a [world][World]. It represents a unique id.
  */
-@JvmInline
 @Serializable
-value class Entity(val id: Int)
+data class Entity(val id: Int, val version: Int = 0)
 
 /**
  * Type alias for an optional hook function for an [EntityService].