diff -up grepmail-5.3104/Makefile.PL.orig grepmail-5.3104/Makefile.PL
--- grepmail-5.3104/Makefile.PL.orig	2017-05-17 21:36:39.272861067 +0200
+++ grepmail-5.3104/Makefile.PL	2017-05-17 21:39:12.910250001 +0200
@@ -2,6 +2,7 @@
 
 use strict;
 
+BEGIN { push @INC, '.'; }
 # For PRIVATE Module::Install extensions
 use lib 'private-lib';