How to change column type for Hashmap's value to LONGTEXT with JPA?

I have an entity with the following fields:

public class P_TABLE2  {

    ...................


    @ElementCollection(fetch = FetchType.LAZY)
    @CollectionTable(name = "P_TABLE1",
            joinColumns = {@JoinColumn(name = "P_ID", referencedColumnName = "P_ID",
                    foreignKey = @ForeignKey(name = "none", value = ConstraintMode.NO_CONSTRAINT))}
    )
    @MapKeyColumn(name="P_KEY")
    @Column(name = "P_VALUE")
    private Map<String, String> bookmarks;

}

Hibernate creates the table P_TABLE1 with following column names:

P_ID      | P_KEY         | P_VALUE
bigint    |  varchar(255) | varchar(255)

I would like to change the data type of P_VALUE from varchar(255) to LONGTEXT. I tried everything, but nothing works.

@Column(name="P_VALUE", columnDefinition="CLOB")
@Column(name="P_VALUE", columnDefinition="TEXT")
@Lob @Column(name="P_VALUE", columnDefinition="TEXT") ====> ERROR

Any suggestions? Pls help me.

PS: I see this question JPA how to set column type to be BLOB for ElementCollection table but if I change the column @Column(name="P_VALUE") to @Column(name="P_VALUE", columnDefinition="BLOB"), it does not work. I deleted the table P_TABLE1 in the datbase, and tried to regenerate the table, but no table is created.