ERROR: data type text[] has no default operator class for access method "gist"

Whenever I try to try to create a GIST index on text[], I get the above error. CREATE TABLE bar(f) AS VALUES (ARRAY['foo','bar','baz']); CREATE INDEX ON bar USING gist(f); ERROR: data type text[] has no default operator class for access method "gist" HINT: You must specify an operator class for the index or define a default operator class for the data type. I'm trying to [create an *Exclusion Constraint*](https://dba.stackexchange.com/a/185177/2639) on bar, so I need a GIST index.