Inflector doesn't pick up inflections

I added 'serie' => 'series' to the Irregularities in inflector_test_cases.rb and got this as test result:

1) Failure:

test_irregularity_between_serie_and_series(InflectorTest)

[./test/inflector_test.rb:189:in `test_irregularity_between_serie_and_series'

./test/../lib/active_support/testing/setup_and_teardown.rb:67:in `__send__'

./test/../lib/active_support/testing/setup_and_teardown.rb:67:in `run']:

<"serie"> expected but was

<"series">.

Yeah it does, but it's kinda funky that custom inflections are overruled by the default uncountables. This isn't documented, and, imho, unwanted behaviour.