diff --git a/Guardfile b/Guardfile
index 1745569..6b90e1e 100644
--- a/Guardfile
+++ b/Guardfile
@@ -1,4 +1,4 @@
-guard 'rspec', :cli => '--format documentation' do
+guard 'rspec', cmd: 'bundle exec rspec --format documentation' do
   watch(%r{^spec/.+_spec\.rb$})
   watch(%r{^lib/(.+)\.rb$})     { |m| "spec/#{m[1]}_spec.rb" }
   watch('spec/spec_helper.rb')  { "spec/" }