use strict; my $module = "amIBeingUsed"; our $RUNTIME_OK = 1; # possible scenarios use amIBeingUsed; # "eurgh, i feel so cheap! slap!!!" eval "use $module"; # "what took you so long to call me? slap!!!" require amIBeingUsed; # "what took you so long to call me?" eval "require $module"; # "what took you so long to call me?"