Relacionamento no Hibernate Annotations

@Entity
@Table(name="autores")
public class Livro {

	@Id
	@GeneratedValue
	private Long id;
	
	@Column(length=100)
	private String nome;

	@ManyToOne
	private Autor autor;
	
	@Column(length=100)
	private String editora;

...

@Entity
@Table(name="autores")
public class Autor {

	@Id
	@GeneratedValue
	private Long id;
	
	@Column(length=100)
	private String nome;

	@OneToMany(mappedBy="autor")
	private Set<Livro> livros;

...

org.hibernate.exception.SQLGrammarException: could not execute query

Caused by: com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: Unknown column 'livro0_.autor_id' in 'field list'