Can anybody tell me whats wrong with my syntax?

SQL> alter table rugby add (constraint uk_rugby unique
(goalie,score) using index tablespace australian_rugby_indx
storage (initial 512M next 512M minextents 2 maxextents 100000
pctincrease 1 freelists 6 )) enable novalidate;
pctincrease 1 freelists 6 )) enable novalidate

ERROR at line 4:
ORA-00905: missing keyword

syntax to enable novalidate constraint