mysql.so isn't found

[Z E]

I am trying to use the taps gem to push my database to Heroku, however, whenever I do the command:

$heroku db:push

I get the following error:

Failed to connect to database:
Sequel::AdapterNotFound -> LoadError: require 'mysql' did not define Mysql::CLIENT_MULTI_RESULTS!
You are probably using the pure ruby mysql.rb driver,
which Sequel does not support. You need to install
the C based adapter, and make sure that the mysql.so
file is loaded instead of the mysql.rb file.

How do I fix this? I am unable to find this mysql.so driver.