diff --git a/Gemfile b/Gemfile
index a9c80b8..a1f9a13 100644
--- a/Gemfile
+++ b/Gemfile
@@ -1,6 +1,6 @@
 source 'http://rubygems.org'
 
-ruby '2.2.0'
+ruby '2.2.3'
 
 gem 'slack-ruby-bot'
 gem 'puma'
diff --git a/slack-mathbot/commands.rb b/slack-mathbot/commands.rb
index defec04..3fb026b 100644
--- a/slack-mathbot/commands.rb
+++ b/slack-mathbot/commands.rb
@@ -1,3 +1,4 @@
 require 'slack-mathbot/commands/calculate'
 require 'slack-mathbot/commands/about'
 require 'slack-mathbot/commands/help'
+require 'slack-mathbot/commands/test'
diff --git a/slack-mathbot/commands/test.rb b/slack-mathbot/commands/test.rb
new file mode 100644
index 0000000..6ca4e0b
--- /dev/null
+++ b/slack-mathbot/commands/test.rb
@@ -0,0 +1,21 @@
+module SlackMathbot
+  module Commands
+    class Test < SlackRubyBot::Commands::Base
+      operator ']'
+      command 'test'
+
+      def self.call(client, data, match)
+          send_message client, data.channel, match
+        result = Dentaku::Calculator.new.evaluate(match[:expression]) if match.names.include?('expression')
+        result = result.to_s if result
+        if result && result.length > 0
+          send_message client, data.channel, result
+        else
+          send_message client, data.channel, 'Got nothing.'
+        end
+      rescue StandardError => e
+        send_message client, data.channel, "Sorry, #{e.message}."
+      end
+    end
+  end
+end