As of mod-mono 1.1.10, there are two ways of configuring mod-mono. The first is to use the pseduo-automatic configuration that Debian uses and the second is to use the zero-configuration version. These are implemented as two different modules for Apache 2. To use the older-style, use the "mod_mono" module to install it. # a2enmod mod_mono To use the auto-configuration, use "mod_mono_auto". # a2enmod mod_mono_auto If both are enabled, the behavior is undefined (and probably doesn't work).