diff --git a/Makefile.PL b/Makefile.PL
index 7bfcb5e..73832f7 100644
--- a/Makefile.PL
+++ b/Makefile.PL
@@ -20,6 +20,7 @@
     'Try::Tiny'      => 0.21,
     'Array::IntSpan' => 2.003,
     'List::MoreUtils' => 0.33,
+    'Parallel::ForkManager' => 1.17,
     'IO::Dir::Recursive' => 0.03,
     'File::Temp'     => 0,
     'Directory::Iterator' => 0,