Liquibase 3.4.1 - unsupported database Exasol issue

I try to get Liquibase working with unsupported database Exasol and get the following error while Liquibase tries to update table DATABASECHANGELOGLOCK:

Unexpected error running Liquibase: Error executing SQL UPDATE LB_EXA.DATABASECHANGELOGLOCK SET LOCK
ED = TRUE, LOCKEDBY = 'XXXXXX(xxx.xx.xx.x)', LOCKGRANTED = '2015-08-14 11:22:00.694' WHERE I
D = 1 AND LOCKED = FALSE: Feature not supported: Incomparable Types: DECIMAL(1,0) and BOOLEAN! (Sess
ion: 1509478963610076197)

I had to adapt create table statement to Exasol syntax before:

CREATE TABLE DATABASECHANGELOGLOCK (
    ID          DECIMAL(10,0) IDENTITY,
    LOCKED      DECIMAL(1),
    LOCKGRANTED TIMESTAMP,
    LOCKEDBY    VARCHAR(255) UTF8
);
ALTER TABLE DATABASECHANGELOGLOCK ADD CONSTRAINT DATABASECHANGELOGLOCK_CON PRIMARY KEY(ID) ENABLE;

Modify the table statement column LOCKED using VARCHAR(5) to fit value FALSE raises another a different error:

Unexpected error running Liquibase: java.lang.ClassCastException: java.lang.Boolean cannot be cast t
o java.lang.Integer

Can anyone help what to do?

Thanks in advance
Lutz