diff --git a/Gemfile b/Gemfile
index 41cc680..460bf04 100644
--- a/Gemfile
+++ b/Gemfile
@@ -1,5 +1,5 @@
 source 'https://rubygems.org'
 
 gem 'test-kitchen'
-gem 'kitchen-docker', '< 2.2.0'
+gem "kitchen-docker", '< 2.2.0'
 gem 'kitchen-ansible'