diff --git a/chapter_01/service.rb b/chapter_01/service.rb
index 2aa6de2..2646660 100644
--- a/chapter_01/service.rb
+++ b/chapter_01/service.rb
@@ -6,7 +6,8 @@
 require "#{File.dirname(__FILE__)}/models/user"
 
 # setting up our environment
-env_arg = ARGV.index("-e")
+env_index = ARGV.index("-e")
+env_arg = ARGV[env_index + 1] if env_index
 env = env_arg || ENV["SINATRA_ENV"] || "development"
 databases = YAML.load_file("config/database.yml")
 ActiveRecord::Base.establish_connection(databases[env])