https://howtoubuntu.org/how-to-install-a-32bit-program-in-64bit-ubuntu Need to state very clear that this is for Ubuntu 12.04 In recent versions everything is different (example for Ubuntu 16.04): ``` sudo dpkg --add-architecture i386 sudo apt-get update sudo apt-get install firefox:i386 ``` Package ia32-libs is obsolete and should not be used anymore. https://help.ubuntu.com/community/MultiArch <bountysource-plugin> --- Want to back this issue? **[Post a bounty on it!](https://www.bountysource.com/issues/65008158-ubuntu-multiarcho-note-is-required-for-recent-ubuntu?utm_campaign=plugin&utm_content=tracker%2F371440&utm_medium=issues&utm_source=github)** We accept bounties via [Bountysource](https://www.bountysource.com/?utm_campaign=plugin&utm_content=tracker%2F371440&utm_medium=issues&utm_source=github). </bountysource-plugin>