diff --git a/utils/models/group_student.js b/utils/models/group_student.js
index aa89620..a23b2fe 100644
--- a/utils/models/group_student.js
+++ b/utils/models/group_student.js
@@ -6,26 +6,10 @@ const Student = require("./student");
 const GroupStudent = sequelize.define(
     "group_student",
     {
-        group: {
-            type: DataTypes.STRING(16),
-            allowNull: false,
-            references: {
-                model: Group,
-                key: "id"
-            }
-        },
-        student: {
-            type: DataTypes.STRING(45),
-            allowNull: false,
-            references: {
-                model: Student,
-                key: "id"
-            }
-        }
     },
     {
         indexes: [{
-            fields: ["group", "student"],
+            fields: ["groupId", "studentId"],
             type: "UNIQUE"
         }]
     }
diff --git a/utils/sequelize.js b/utils/sequelize.js
index 5368e16..cbb0d8f 100644
--- a/utils/sequelize.js
+++ b/utils/sequelize.js
@@ -49,7 +49,9 @@ Timetable.belongsTo(Teacher);
 Timetable.belongsTo(Room);
 
 Person.hasOne(Student);
+Student.belongsTo(Person);
 Person.hasOne(Teacher);
+Student.belongsTo(Person);
 
 Teacher.belongsTo(Room);