Map Right Alt to Alt instead of AltGr

I have a Kinesis Advantage keyboard and I'm trying to make it so that my right and left Alt keys do the same thing. Currently the left Alt key works as expected but the right Alt key just allows me to type foreign characters. I found the following answer to another question to be very helpful, but I can't get similar results. Here's what I see when I type xmodmap: $ xmodmap xmodmap: up to 4 keys per modifier, (keycodes in parentheses): shift Shift_L (0x32), Shift_R (0x3e) lock control Control_L (0x25), Control_R (0x69) mod1 Alt_L (0x40), Meta_L (0xcd) mod2 Num_Lock (0x4d) mod3 mod4 Super_L (0x85), Super_R (0x86), Super_L (0xce), Hyper_L (0xcf) mod5 ISO_Level3_Shift (0x5c), Mode_switch (0xcb) In my case I don't have an Alt_R key mapped to any of my mod keys. When that's the case what should I do?