Problème clé étrangère sous oracle

CREATE TABLE Voyageur(
numV NUMBER(4) NOT NULL PRIMARY KEY CONSTRAINT check_numV
     CHECK(numV LIKE'[!a-zA-Z]') DISABLE,
nomV VARCHAR(15) NOT NULL CONSTRAINT check_nomV
     CHECK(nomV LIKE'[!0-9]') DISABLE,
prenomV VARCHAR(15) NOT NULL CONSTRAINT check_prenomV
     CHECK(prenomV LIKE'[!0-9]')DISABLE,
birthdayV DATE NOT NULL DISABLE,
addressV VARCHAR(50) NOT NULL DISABLE,
telV VARCHAR(20) NOT NULL CONSTRAINT check_telV
     CHECK(telV LIKE'[+]%' AND telM LIKE'[!a-zA-Z]') DISABLE,
idCat NUMBER(1) NOT NULL DISABLE,
[color=red]FOREIGN KEY(idCat) REFERENCES Categorie(idCat)[/color]
);

CREATE TABLE Categorie(
idCat NUMBER(1) NOT NULL DISABLE,
nomCat VARCHAR(20) NOT NULL CONSTRAINT check_nomCat
       CHECK(nomCat IN('insulaire','normale','insulairesecondaire'))  DISABLE,
reduction  NUMBER(3) NOT NULL  CONSTRAINT check_reduction
          CHECK(reduction IN ( '25' , '50' , '100' )) DISABLE,
PRIMARY KEY(idCat)
);