Construct filter with colon does not work

[j9a8m7i6e]

Constructing filter with search value that contains a colon cuts everything off after colon.

For example:
ldap_filter = "cn=Doe, Jane: IT"
filter = Net::LDAP::Filter.construct( ldap_filter )
puts filter

this returns:
(cn=Doe, Jane)

I'm assuming this is not intended functionality.