Yacc bug in sql_parser.y ?

Hi, all. Still trying to get rolling averages out of my MonetDB database, and I ran into this:

Line 3954 of sql_parser.y,

window_frame_end: UNBOUNDED FOLLOWING { $$ = _symbol_create_int(SQL_FRAME, -1); } | window_frame_following { $$ = $1; } | CURRENT ROW { $$ = _symbol_create_int(SQL_FRAME, 0); } ;

window_frame_following: value_exp PRECEDING { $$ = $1; } ;

Should that not be "value_exp FOLLOWING "?