A Database Error Occurred

Error Number: 1052

Column 'langCod' in where clause is ambiguous

SELECT *, IF( LENGTH(fotExt) > 4, fotExt, CONCAT(fotID, fotExt)) as imagem FROM (produtos P ) LEFT JOIN pr_fotos F ON P.proCod = F.id AND fotPrincipal=1 LEFT JOIN categoria C ON P.catCod = C.catCod WHERE `C`.`catCod` = '4' AND `langCod` = 2 LIMIT 1000