User name case insensitivity

I would like for my FreeRADIUS 3.0.20 server to match user names to be authenticated in a case-insensitive way. To that effect, I changed the contents of /etc/raddb/mods-enabled/sradutmp as follows: radutmp sradutmp { filename = ${logdir}/sradutmp case_sensitive = "no" permissions = 0644 caller_id = "no" } When I launch the FreeRADIUS server with -sfXx in the resulting traces I can see that the module above has been loaded, and that the case_sensitive attribute is indeed set to "no". However, the FreeRADIUS server remains user name case-sensitive. What am I misunderstanding here?