diff --git a/script/korapxml2krill b/script/korapxml2krill
index 72ba265..05beb09 100644
--- a/script/korapxml2krill
+++ b/script/korapxml2krill
@@ -553,6 +553,7 @@
 In case everything went well, the C<korapxml2krill> tool will
 be available on your command line immediately.
 Minimum requirement for L<KorAP::XML::Krill> is Perl 5.14.
+In addition to work with zip archives, the C<unzip> tool needs to be present.
 
 =head1 ARGUMENTS
 
@@ -588,6 +589,9 @@
 In this case further archives lacking a C<.> root folder
 need to be passed with a hash sign in front of the archive's name.)
 
+B<To support zip files, a version of C<unzip> needs to be installed that is
+compatible with the archive file.>
+
 B<The root folder switch is experimental and may vanish in future versions.>
 
 =item B<--output|-o> <directory|file>