diff --git a/lib/guard/puppet/runner.rb b/lib/guard/puppet/runner.rb
index 647ec70..535b576 100644
--- a/lib/guard/puppet/runner.rb
+++ b/lib/guard/puppet/runner.rb
@@ -21,6 +21,12 @@ module Guard
 
         begin
           maybe_bundle_with_env do
+            # TODO: hack, untested, needed to avoid:
+            #
+            #"Error: Could not initialize global default settings:
+            #  Attempting to initialize global default settings more than once!"
+            ::Puppet.settings.send(:clear_everything_for_tests)
+
             ::Puppet::Util::CommandLine.new('puppet', command_line_params).execute
           end
           0