diff --git a/manifests/params.pp b/manifests/params.pp
index fa65c2c34..b8def7dd8 100644
--- a/manifests/params.pp
+++ b/manifests/params.pp
@@ -256,6 +256,7 @@
 
     'Gentoo': {
       $client_package_name = 'virtual/mysql'
+      $includedir          = undef
       $server_package_name = 'virtual/mysql'
       $basedir             = '/usr'
       $config_file         = '/etc/mysql/my.cnf'