Updating field based on matched data from two seperate tables in SQL

[kperoni]

I want to update the workstation table field m3 with the value '498', where the sw table's m2 field is equal to the workstation table's m5 field.

I can't get it to work, is this anywhere close?

UPDATE workstation SET m3='498'
WHERE
(sw.m2 = workstation.m5)

[TTVN]

that should work