Select MAX timestamp with JPA2 Criteria API

So my entity has:

@Column(name="TS", nullable=false)
private java.sql.Timestamp timestamp; 

My generated MetaModel has:

public static volatile SingularAttribute<MyEntity,Timestamp> timestamp;

I want to select by the Max Timestamp value:

Root<MyEntity> root = query.from(MyEntity.class);
Expression maxExpression = cb.max(root.get(MyEntity_.timestamp));

But I am not allowed because:

max(Expression<N> x) Create an aggregate expression applying the numerical max operation. <N extends java.lang.Number> Expression

Of course Timestamp does not extend Number.

How can I do a MAX on a Timestamp column using the typesafe Criteria API ?