EX7300 range extender hands out IP addresses when in AP mode

I have an EX7300 running in wifi extender mode, and it works well. I'd like to hard-wire the connection back to my main network and use it just as an access point. I'd like to use the DHCP server on my network rather than anything internal to the EX7300. After switching the mode to Access Point, the extender started handing out 192.168.1.x addresses to my wireless clients. This is not the IP range I use on my network. From what I've read in the manual it doesn't look like this is supposed to happen. Can somebody tell me why the AP would be handing out IP addresses, and how to disable it?