Foreign key constraint is incorrectly formed

[Salvador Castillo]

CREATE TABLE Usuario(

Idusuario INTEGER PRIMARY KEY AUTO_INCREMENT,
Idrol int NOT NULL,
Nombre VARCHAR(100) NOT NULL,
TipoDoc VARCHAR(20) NULL,
NumDoc VARCHAR(20) NULL,
Direccion VARCHAR(70) NULL,
Telefono VARCHAR(20) NULL,
Email VARCHAR(50) NOT NULL,
Password_Hash TINYBLOB NOT NULL,
Password_Salt TINYBLOB NOT NULL,
Condicion TINYINT DEFAULT(1),
FOREIGN KEY (Idrol) REFERENCES Role (Idrol)

);

send me this error. the table Role exist and is int (11). any help please