Require the verbatim package (similar to the LaTeX version).
diff --git a/Doc/perl/howto.perl b/Doc/perl/howto.perl
index ee8f3a4..5fe3eb5 100644
--- a/Doc/perl/howto.perl
+++ b/Doc/perl/howto.perl
@@ -5,7 +5,8 @@
 
 package main;
 
-&do_require_package("article");
-&do_require_package("python");
+do_require_package("article");
+do_require_package("verbatim");
+do_require_package("python");
 
 1;				# sheesh....