Aspyr has updated Civilization IV and its expansion pack, Civilization IV Warlords.

The updates are available as free downloads from

Civilization IV 1.61 Rev C will fully update any previous version of the game and is recommended for all users, Aspyr said. The update fixes a sound problem introduced by a previous update.

Civilization IV: Warlords 1.0 Rev B also fixes a similar audio problem and will update any previous version of Civilization 4: Warlords. It also contains over 100 bug fixes, the company said.