diff --git a/manifests/init.pp b/manifests/init.pp
index e712f6f..bedc2db 100644
--- a/manifests/init.pp
+++ b/manifests/init.pp
@@ -20,6 +20,12 @@ class bandersnatch (
   $bandersnatch_source = 'pip',
 ) {
 
+  if ! defined(Package['mercurial']) {
+    package { 'mercurial':
+      ensure => present,
+    }
+  }
+
   if ($bandersnatch_source == 'pip') {
     package { 'bandersnatch':
       ensure   => 'present',