Can I get bundler t use an earlier gem?

Question

Hi,

I'm trying to get my rails3 app & gem taps & heroku to play nicely together. One googled solution is to use an earlier version of sequel. So I'd like to try to have bundler use sequel v3.13.0 instead of sequel v3.15.0, but bundler says:

You have requested:
sequel = 3.13.0

The bundle currently has sequel locked at 3.15.0.
Try running `bundle update sequel`

It could be dependencies thats preventing this - how do I find out? Can I do this some other way? thanks...