validate issue - char converted to varchar2(255) in Oracle

Deployment in Tomcat I get this issue with one of my persistent object, deployment issue 'Wrong column type FGTADM.CABIN_CLASSES for column class_code. Found: char, expected: varchar2(255 char).

I think the issue is with the Oracle dialect and how it converts a java String type to varchar2(255); regardless of what is on set on the @Column annotation; in particular the columnDefinition='char' setting is ignored.

Currently the class that errors on deployment is annotated like this:
public class CabinClass extends FareGateObject {

@Id
@Column(name = "class_code", length=1, columnDefinition = "char")
private String classCode;

The Oracle cabin_class table is structured like this:
COLUMN_NAME TYPE_NAME COLUMN_SIZE
CLASS_CODE CHAR 1
CLASS_NAME VARCHAR2 15
DESCRIPTION VARCHAR2 200

Any help appreciated. Do I need to upgrade hibernate? Is the @Column annotation definition correct?

regards
geoffpowdrell