Bundler could not find compatible versions for gem mime-types

Super baffled by this problem. Everything is working great local but when I deploy to Heroku it hits this error:

Bundler could not find compatible versions for gem "mime-types":
In Gemfile:
rails (= 3.2.17) ruby depends on
mime-types (~> 1.16) ruby
stripe (>= 0) ruby depends on
mime-types (2.3)

I've tried gem installing mime-types 2.3 both in the gemfile and from the command line and neither have given any great results, though maybe it's from my lack of experience.

If I had hair I'd be pulling it out! Again, this problem only happens when deploying to Heroku. Everything bundle installs and updates fine locally.

Solution

I was able to resolve a similar problem:

Bundler could not find compatible versions for gem "mime-types":
  In Gemfile:
    rails (= 4.0.7) ruby depends on
      mime-types (~> 1.16) ruby

    stripe (~> 1.15.0) ruby depends on
      mime-types (2.3)

By throwing away my Gemfile.lock and running bundle install.

Hope this helps!