diff --git a/src/main/java/koz01/java2/lab10/BaseEntity.java b/src/main/java/koz01/java2/lab10/BaseEntity.java
index d7afffe1791ce863db29f658a3002312b811a801..98683c11fb2c089f1887bb5102c1bc553a90550c 100644
--- a/src/main/java/koz01/java2/lab10/BaseEntity.java
+++ b/src/main/java/koz01/java2/lab10/BaseEntity.java
@@ -15,6 +15,7 @@ import lombok.ToString;
 @ToString
 public class BaseEntity implements Serializable {
 
+	private static final long serialVersionUID = 1L;
 	@Getter
 	@Id
 	@GeneratedValue(strategy = GenerationType.AUTO)
diff --git a/src/main/java/koz01/java2/lab10/Clas.java b/src/main/java/koz01/java2/lab10/Clas.java
index 6c0e5515493432d65e1f85f97532c6569d6df28c..2d67f8d757e498adba23f107797781338c75b739 100644
--- a/src/main/java/koz01/java2/lab10/Clas.java
+++ b/src/main/java/koz01/java2/lab10/Clas.java
@@ -14,6 +14,8 @@ import lombok.Setter;
 @NoArgsConstructor
 public class Clas extends BaseEntity {
 
+	private static final long serialVersionUID = 1L;
+
 	@Getter
 	@Setter
 	private String cname;
diff --git a/src/main/java/koz01/java2/lab10/Department.java b/src/main/java/koz01/java2/lab10/Department.java
index ab1b47ead87b8c8a2ae15ee0b9e41116af13ede5..b49b7d237754389ef7249b598d2154036df5f102 100644
--- a/src/main/java/koz01/java2/lab10/Department.java
+++ b/src/main/java/koz01/java2/lab10/Department.java
@@ -16,6 +16,8 @@ import lombok.ToString;
 @NoArgsConstructor
 public class Department extends BaseEntity {
 
+	private static final long serialVersionUID = 1L;
+
 	@Getter
 	@Setter
 	private String name;
diff --git a/src/main/java/koz01/java2/lab10/Employee.java b/src/main/java/koz01/java2/lab10/Employee.java
index 4d9be7cc35e5399ab1a949c8864ed1113bb318e3..68f522d1f7da3ac1e73093412a48c4f1bfe55c03 100644
--- a/src/main/java/koz01/java2/lab10/Employee.java
+++ b/src/main/java/koz01/java2/lab10/Employee.java
@@ -14,6 +14,8 @@ import lombok.ToString;
 @NoArgsConstructor
 public class Employee extends BaseEntity {
 
+	private static final long serialVersionUID = 1L;
+
 	@Getter
 	@Setter
 	private String ename;
diff --git a/src/main/java/koz01/java2/lab10/NonTeachingStaff.java b/src/main/java/koz01/java2/lab10/NonTeachingStaff.java
index c2f216f5d1248bac9435be2be5601e60a85d45e0..6f55bb5874a8ce5733dfd85a811607d5b475d82e 100644
--- a/src/main/java/koz01/java2/lab10/NonTeachingStaff.java
+++ b/src/main/java/koz01/java2/lab10/NonTeachingStaff.java
@@ -9,6 +9,7 @@ import lombok.Setter;
 @NoArgsConstructor
 public class NonTeachingStaff extends Staff {
 
+	private static final long serialVersionUID = 1L;
 	@Getter
 	@Setter
 	private String areaexpertise;
diff --git a/src/main/java/koz01/java2/lab10/Staff.java b/src/main/java/koz01/java2/lab10/Staff.java
index e2a4540626210e7fb0f001fa10b26945b38ac501..4933d8fd6732f0079fc7ff11d0d913e976e0acae 100644
--- a/src/main/java/koz01/java2/lab10/Staff.java
+++ b/src/main/java/koz01/java2/lab10/Staff.java
@@ -10,6 +10,7 @@ import lombok.Setter;
 public class Staff extends BaseEntity {
 
 
+	private static final long serialVersionUID = 1L;
 	@Getter
 	@Setter
 	private String sname;
diff --git a/src/main/java/koz01/java2/lab10/Teacher.java b/src/main/java/koz01/java2/lab10/Teacher.java
index de64c87886ff9e564d5a670b3ef91d78bffab8c5..a5738bf2ac79b3dd10ce30c1ef51ea488d6fa3f7 100644
--- a/src/main/java/koz01/java2/lab10/Teacher.java
+++ b/src/main/java/koz01/java2/lab10/Teacher.java
@@ -15,6 +15,8 @@ import lombok.Setter;
 @NoArgsConstructor
 public class Teacher extends BaseEntity {
 
+	private static final long serialVersionUID = 1L;
+
 	@Getter
 	@Setter
 	private String tname;