psql UPDATE field [tab] expands to DEFAULT?

UPDATE my_table SET my_field 

(with a trailing space)

and then hit Tab, it will expand that to an =, and then another tab will expand to DEFAULT, so that I then have:

UPDATE my_table SET my_field = DEFAULT

If I'm tabbing out in this situation, it's going to be after the =, and I will have typed "myreal"[tab] in the vain hope that psql will complete that to "myreallylongfieldname," but instead it gets replaced with DEFAULT.
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