Here's an alternative that doesn't use a loop:

package MyModule;

use vars qw(@ISA);
BEGIN {
   @ISA = ...;
   *MyModule::Super::ISA = \@ISA;
}

sub dostuff {
   if (...condition...) {
      if (my $method = MyModule::Super->can('dostuff')) {
         goto $method;
      }
      ...die?...
   }

   ...
}
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You probably know that dostuff exists in a parent, you can simplify it down to:

package MyModule;

use vars qw(@ISA);
BEGIN {
   @ISA = ...;
   *MyModule::Super::ISA = \@ISA;
}

sub dostuff {
   goto(MyModule::Super->can('dostuff')) if (...condition...);

   ...
}
[download]

Don't put any methods (or at least not 'dostuff') in the MyModule::Super package (namespace) for this to work.