Maxdepth command not working in AIX.Need alternative solution for this command

Hi All,

I am trying to select 30 days older files under current directory ,but not from subdirectory using below command.

find  <Dir> -type f -mtime + 30

This command selecting all the files from current directory and also from sub directory .

I read some documention through internet , most of them suggested to use "-maxdepth" command. but this command is not working in AIX .
kindly help me for any other alternative solution ?

Name the start dir . and prune all others

find <Dir>/. ! -name . -prune -type f -mtime +30