Conflict between ruby & jruby bundle install

When I run the ‘bundle install’ command from the main directory of my
ruby on rails (version 3) app, I get the following error:

Installing sqlite3 (1.3.3) with native extensions
`build_extensions’: ERROR: Failed to build gem native extension.

In my path variable, I have ruby before jruby, so why is jruby being
run? How can I resolve this issue? Thanks.