diff --git a/ocpp-common/src/main/java/eu/chargetime/ocpp/model/Validatable.java b/ocpp-common/src/main/java/eu/chargetime/ocpp/model/Validatable.java
index 215c8771..d39da22c 100644
--- a/ocpp-common/src/main/java/eu/chargetime/ocpp/model/Validatable.java
+++ b/ocpp-common/src/main/java/eu/chargetime/ocpp/model/Validatable.java
@@ -27,8 +27,10 @@ of this software and associated documentation files (the "Software"), to deal
 SOFTWARE.
 */
 
+import java.io.Serializable;
+
 /** Interface used to add a validation option on a model. */
-public interface Validatable {
+public interface Validatable extends Serializable {
   /**
    * Validate if the model lives up to the specification. Must check if required fields are
    * correctly set and underlying models are valid.