diff --git a/Gemfile b/Gemfile
index 01c3725..431bac8 100644
--- a/Gemfile
+++ b/Gemfile
@@ -1,2 +1,4 @@
 source :rubygems
 gem 'rulers', :path => "../rulers"
+# Book version pg. 16 shows:  gem 'rulers'  # Your gem name
+# Shouldn't it match this source code?