diff --git a/spec/acceptance/mysql_server_spec.rb b/spec/acceptance/mysql_server_spec.rb
index 8589ea2..06ea0ba 100644
--- a/spec/acceptance/mysql_server_spec.rb
+++ b/spec/acceptance/mysql_server_spec.rb
@@ -2,12 +2,14 @@ require 'spec_helper_acceptance'
 
 describe 'mysql class' do
   describe 'advanced config' do
-    let(:tmpdir) { default.tmpdir('mysql') }
+    before(:all) do
+      @tmpdir = default.tmpdir('mysql')
+    end
     let(:pp) do
       <<-EOS
         class { 'mysql::server':
-          config_file             => '#{tmpdir}/my.cnf',
-          includedir              => '#{tmpdir}/include',
+          config_file             => '#{@tmpdir}/my.cnf',
+          includedir              => '#{@tmpdir}/include',
           manage_config_file      => 'true',
           override_options        => { 'mysqld' => { 'key_buffer_size' => '32M' }},
           package_ensure          => 'present',