Hibernate one to one unidirectional - ids not assigned

On my unit tests I get the JpaSystemException: ids for this class must be manually assigned before calling save() error. I have reworded my entities to make the question shorter and more readable.

So student has an optional one to one relation with the table EnrolledInfo.

Student Entity

@Entity
@Table(name = "Student")
public class Student  {

    @Id
    @Column(name = "studentId")
    @GeneratedValue(strategy = GenerationType.AUTO)
    private Long studentId;

    @OneToOne(fetch = FetchType.LAZY, mappedBy = "student", cascade = CascadeType.ALL)
    private EnrolledInfo enrolledInfo;

    private String firstName;

    private String lastName;

    // setters&getters etc..    
}

EnrolledInfo Entity

@Entity
@Table(name = "EnrolledInfo")
public class EnrolledInfo implements Serializable {

    @Id
    private Long studentId;

    @OneToOne(fetch = FetchType.Eager)
    @PrimaryKeyJoinColumn
    @JsonBackReference
    private Student student;

    @Column(name = "enrolledDate")
    private Date enrolledDate;

    @Column(name = "paidTuition")
    private Boolean paidTuition;

    // setters&getters etc..
}

Putting it together in a test (this errors)

Surely I dont have to save the enrolledInfo entity before I save the student one?

@Test
public void student_test() {

  Student student = new Student();
  EnrolledInfo enrolledInfo = new EnrolledInfo(); 
  enrolledInfo.setPaidTuition(true);

  student.setEnrolledInfo(enrolledInfo);        
  studentDao.save(student);
  // errors on // JpaSystemException: ids for this class must be manually assigned before calling save():
}