"SQL command not properly ended" on update with inner join

Question

What on earth am I doing wrong here? It gives me "SQL command not properly ended"

UPDATE RNP_PROF_ESP_CAT RPEC SET RPEC.RNP_ESPECIALIDADES_ID = 181
INNER JOIN RNP_PROF_ORDEM RPO ON RPO.RNP_PROF_IDENT_ID = RPEC.RNP_PROF_IDENT_ID 
WHERE RPO.N_CEDULA = '456258';

Answer 1

Found the answer:

UPDATE RNP_PROF_ESP_CAT RPEC SET RPEC.RNP_ESPECIALIDADES_ID = 181
WHERE EXISTS (SELECT 1 FROM RNP_PROF_ORDEM RPO WHERE RPO.N_CEDULA = '456258' AND RPO.RNP_PROF_IDENT_ID = RPEC.RNP_PROF_IDENT_ID);

Answer 2

UPDATE RPEC
SET RPEC.RNP_ESPECIALIDADES_ID = 181
FROM RNP_PROF_ESP_CAT RPEC
INNER JOIN RNP_PROF_ORDEM RPO ON RPO.RNP_PROF_IDENT_ID = RPEC.RNP_PROF_IDENT_ID 
WHERE RPO.N_CEDULA = '456258';