diff --git a/src/main/java/com/auth0/json/auth/UserInfo.java b/src/main/java/com/auth0/json/auth/UserInfo.java
index 25e07898..df7f04e3 100644
--- a/src/main/java/com/auth0/json/auth/UserInfo.java
+++ b/src/main/java/com/auth0/json/auth/UserInfo.java
@@ -5,6 +5,7 @@
 import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
 import com.fasterxml.jackson.annotation.JsonInclude;
 
+import java.io.Serializable;
 import java.util.HashMap;
 import java.util.Map;
 
@@ -14,7 +15,7 @@
  */
 @JsonIgnoreProperties(ignoreUnknown = true)
 @JsonInclude(JsonInclude.Include.NON_NULL)
-public class UserInfo {
+public class UserInfo implements Serializable {
 
     private Map<String, Object> values;
 
diff --git a/src/main/java/com/auth0/json/mgmt/users/Identity.java b/src/main/java/com/auth0/json/mgmt/users/Identity.java
index f8008a65..d739edf9 100644
--- a/src/main/java/com/auth0/json/mgmt/users/Identity.java
+++ b/src/main/java/com/auth0/json/mgmt/users/Identity.java
@@ -2,13 +2,14 @@
 
 import com.fasterxml.jackson.annotation.*;
 
+import java.io.Serializable;
 import java.util.HashMap;
 import java.util.Map;
 
 @SuppressWarnings({"unused", "WeakerAccess"})
 @JsonIgnoreProperties(ignoreUnknown = true)
 @JsonInclude(JsonInclude.Include.NON_NULL)
-public class Identity {
+public class Identity implements Serializable {
 
     @JsonProperty("connection")
     private String connection;
diff --git a/src/main/java/com/auth0/json/mgmt/users/ProfileData.java b/src/main/java/com/auth0/json/mgmt/users/ProfileData.java
index 9edf6f5f..61fc505c 100644
--- a/src/main/java/com/auth0/json/mgmt/users/ProfileData.java
+++ b/src/main/java/com/auth0/json/mgmt/users/ProfileData.java
@@ -2,13 +2,14 @@
 
 import com.fasterxml.jackson.annotation.*;
 
+import java.io.Serializable;
 import java.util.HashMap;
 import java.util.Map;
 
 @SuppressWarnings({"unused", "WeakerAccess"})
 @JsonIgnoreProperties(ignoreUnknown = true)
 @JsonInclude(JsonInclude.Include.NON_NULL)
-public class ProfileData {
+public class ProfileData implements Serializable {
 
     @JsonProperty("email")
     private String email;
diff --git a/src/main/java/com/auth0/json/mgmt/users/User.java b/src/main/java/com/auth0/json/mgmt/users/User.java
index b44c4053..00282a16 100644
--- a/src/main/java/com/auth0/json/mgmt/users/User.java
+++ b/src/main/java/com/auth0/json/mgmt/users/User.java
@@ -2,6 +2,7 @@
 
 import com.fasterxml.jackson.annotation.*;
 
+import java.io.Serializable;
 import java.util.Date;
 import java.util.HashMap;
 import java.util.List;
@@ -13,7 +14,7 @@
 @SuppressWarnings({"unused", "WeakerAccess"})
 @JsonIgnoreProperties(ignoreUnknown = true)
 @JsonInclude(JsonInclude.Include.NON_NULL)
-public class User {
+public class User implements Serializable {
 
     @JsonProperty("client_id")
     private String clientId;