JPA OneToMany with same entity using JoinTable

Question

I have a OneToMany relationship that I need to model in JPA. I have a class called CustomerItem that needs to have certain CustomerItems (list) related to it. Therefore, I modeled it using JoinTable to keep this in a separate table.

I've tried to model it like this:

    @OneToMany(cascade = CascadeType.ALL, fetch = FetchType.LAZY)
    @JoinTable(name = "mp_related_item", joinColumns = {
    @JoinColumn(name = "customer_item_id", referencedColumnName = "id")})
           private Set<CustomerItem> relatedItems;

I've created my table using Liquibase:

<createTable tableName="MP_RELATED_ITEM">
        <column autoIncrement="true" name="ID" type="BIGINT">
            <constraints primaryKey="true"
                primaryKeyName="PK_MP_RELATED_ITEMS" />
        </column>
        <column name="CUSTOMER_ITEM_ID" type="BIGINT" />
        <column name="RELATED_ITEM_ID" type="BIGINT" />
</createTable>

However, this results in an exception when trying to load relatedItems for a specific CustomerItem:

    com.microsoft.sqlserver.jdbc.SQLServerException: Ogiltigt kolumnnamn, 'relatedItems_ID'. (Illegal column name)

What am I doing wrong here? When I check the generated query it seems like the persistence framework thinks that relatedItems is one single entity, when in reality it's a list of multiple entities that I want to load.