diff --git a/puppet/modules/colab/manifests/init.pp b/puppet/modules/colab/manifests/init.pp
index 16e001e..36f7882 100644
--- a/puppet/modules/colab/manifests/init.pp
+++ b/puppet/modules/colab/manifests/init.pp
@@ -26,6 +26,7 @@ class colab {
   exec { 'newaliases':
     path        => '/usr/bin/newaliases',
     refreshonly => true,
+    require     => Class['postfix'],
   }
 
   group { 'colab':
--
libgit2 0.21.2