diff --git a/Gemfile.lock b/Gemfile.lock
index c3b2541..8de5f9c 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -1,63 +1,75 @@
 GEM
   remote: https://rubygems.org/
   specs:
-    abstract_type (0.0.7)
-    adamantium (0.2.0)
-      ice_nine (~> 0.11.0)
-      memoizable (~> 0.4.0)
-    aruba (0.9.0)
+    activesupport (4.2.5.1)
+      i18n (~> 0.7)
+      json (~> 1.7, >= 1.7.7)
+      minitest (~> 5.1)
+      thread_safe (~> 0.3, >= 0.3.4)
+      tzinfo (~> 1.1)
+    aruba (0.13.0)
       childprocess (~> 0.5.6)
       contracts (~> 0.9)
       cucumber (>= 1.3.19)
       ffi (~> 1.9.10)
       rspec-expectations (>= 2.99)
       thor (~> 0.19)
-    ast (2.1.0)
-    astrolabe (1.3.1)
-      parser (~> 2.2)
+    ast (2.2.0)
+    axiom-types (0.1.1)
+      descendants_tracker (~> 0.0.4)
+      ice_nine (~> 0.11.0)
+      thread_safe (~> 0.3, >= 0.3.1)
     bindata (2.1.0)
     builder (3.2.2)
-    childprocess (0.5.6)
+    childprocess (0.5.9)
       ffi (~> 1.0, >= 1.0.11)
+    codeclimate-engine-rb (0.3.1)
+      virtus (~> 1.0)
     codeclimate-test-reporter (0.4.8)
       simplecov (>= 0.7.1, < 1.0.0)
     coderay (1.1.0)
-    concord (0.1.5)
-      adamantium (~> 0.2.0)
-      equalizer (~> 0.0.9)
-    contracts (0.12.0)
-    coveralls (0.8.2)
+    coercible (1.0.0)
+      descendants_tracker (~> 0.0.1)
+    contracts (0.13.0)
+    coveralls (0.8.10)
       json (~> 1.8)
       rest-client (>= 1.6.8, < 2)
-      simplecov (~> 0.10.0)
+      simplecov (~> 0.11.0)
       term-ansicolor (~> 1.3)
       thor (~> 0.19.1)
-    cucumber (2.1.0)
+      tins (~> 1.6.0)
+    cucumber (2.3.2)
       builder (>= 2.1.2)
-      cucumber-core (~> 1.3.0)
+      cucumber-core (~> 1.4.0)
+      cucumber-wire (~> 0.0.1)
       diff-lcs (>= 1.1.3)
-      gherkin3 (~> 3.1.0)
+      gherkin (~> 3.2.0)
       multi_json (>= 1.7.5, < 2.0)
       multi_test (>= 0.1.2)
-    cucumber-core (1.3.0)
-      gherkin3 (~> 3.1.0)
+    cucumber-core (1.4.0)
+      gherkin (~> 3.2.0)
+    cucumber-wire (0.0.1)
+    descendants_tracker (0.0.4)
+      thread_safe (~> 0.3, >= 0.3.1)
     diff-lcs (1.2.5)
     docile (1.1.5)
-    domain_name (0.5.24)
+    domain_name (0.5.20160128)
       unf (>= 0.0.5, < 1.0.0)
     equalizer (0.0.11)
+    erubis (2.7.0)
     ffi (1.9.10)
-    flay (2.6.1)
+    flay (2.7.0)
+      erubis (~> 2.7.0)
       ruby_parser (~> 3.0)
       sexp_processor (~> 4.0)
     flog (4.3.2)
       ruby_parser (~> 3.1, > 3.1.0)
       sexp_processor (~> 4.4)
     formatador (0.2.5)
-    gherkin3 (3.1.1)
-    given_core (3.7.1)
+    gherkin (3.2.0)
+    given_core (3.8.0)
       sorcerer (>= 0.3.7)
-    gli (2.13.2)
+    gli (2.13.4)
     guard (2.13.0)
       formatador (>= 0.2.4)
       listen (>= 2.7, <= 4.0)
@@ -81,85 +93,84 @@ GEM
       rubocop (~> 0.20)
     http-cookie (1.0.2)
       domain_name (~> 0.5)
-    ice_nine (0.11.1)
+    i18n (0.7.0)
+    ice_nine (0.11.2)
     inch (0.7.0)
       pry
       sparkr (>= 0.2.0)
       term-ansicolor
       yard (~> 0.8.7.5)
     json (1.8.3)
-    listen (3.0.3)
+    listen (3.0.6)
       rb-fsevent (>= 0.9.3)
-      rb-inotify (>= 0.9)
-    lumberjack (1.0.9)
-    memoizable (0.4.2)
-      thread_safe (~> 0.3, >= 0.3.1)
+      rb-inotify (>= 0.9.7)
+    lumberjack (1.0.10)
     method_source (0.8.2)
-    mime-types (2.6.2)
+    mime-types (2.99)
+    minitest (5.8.4)
     multi_json (1.11.2)
     multi_test (0.1.2)
-    nenv (0.2.0)
-    netrc (0.10.3)
+    nenv (0.3.0)
+    netrc (0.11.0)
     notiffany (0.0.8)
       nenv (~> 0.1)
       shellany (~> 0.0)
-    parser (2.2.2.6)
-      ast (>= 1.1, < 3.0)
-    phut (0.6.11)
-      gli (~> 2.13.2)
-      pio (~> 0.27.0)
-      pry (~> 0.10.1)
-    pio (0.27.1)
+    parser (2.3.0.6)
+      ast (~> 2.2)
+    phut (0.7.7)
+      activesupport (~> 4.2, >= 4.2.5)
+      gli (~> 2.13.4)
+      pio (~> 0.30.0)
+      pry (~> 0.10.3)
+    pio (0.30.0)
+      activesupport (~> 4.2, >= 4.2.4)
       bindata (~> 2.1.0)
     powerpack (0.1.1)
-    private_attr (1.1.0)
-    procto (0.0.2)
-    pry (0.10.2)
+    pry (0.10.3)
       coderay (~> 1.1.0)
       method_source (~> 0.8.1)
       slop (~> 3.4)
-    rainbow (2.0.0)
-    rake (10.4.2)
-    rb-fsevent (0.9.6)
-    rb-inotify (0.9.5)
+    rainbow (2.1.0)
+    rake (10.5.0)
+    rb-fsevent (0.9.7)
+    rb-inotify (0.9.7)
       ffi (>= 0.5.0)
-    reek (3.5.0)
-      parser (~> 2.2.2.5)
-      private_attr (~> 1.1)
+    reek (3.10.2)
+      codeclimate-engine-rb (~> 0.3.1)
+      parser (~> 2.3, >= 2.3.0.6)
       rainbow (~> 2.0)
-      unparser (~> 0.2.2)
     rest-client (1.8.0)
       http-cookie (>= 1.0.2, < 2.0)
       mime-types (>= 1.16, < 3.0)
       netrc (~> 0.7)
-    rspec (3.3.0)
-      rspec-core (~> 3.3.0)
-      rspec-expectations (~> 3.3.0)
-      rspec-mocks (~> 3.3.0)
-    rspec-core (3.3.2)
-      rspec-support (~> 3.3.0)
-    rspec-expectations (3.3.1)
+    rspec (3.4.0)
+      rspec-core (~> 3.4.0)
+      rspec-expectations (~> 3.4.0)
+      rspec-mocks (~> 3.4.0)
+    rspec-core (3.4.2)
+      rspec-support (~> 3.4.0)
+    rspec-expectations (3.4.0)
       diff-lcs (>= 1.2.0, < 2.0)
-      rspec-support (~> 3.3.0)
-    rspec-given (3.7.1)
-      given_core (= 3.7.1)
+      rspec-support (~> 3.4.0)
+    rspec-given (3.8.0)
+      given_core (= 3.8.0)
       rspec (>= 2.14.0)
-    rspec-mocks (3.3.2)
+    rspec-mocks (3.4.1)
       diff-lcs (>= 1.2.0, < 2.0)
-      rspec-support (~> 3.3.0)
-    rspec-support (3.3.0)
-    rubocop (0.34.2)
-      astrolabe (~> 1.3)
-      parser (>= 2.2.2.5, < 3.0)
+      rspec-support (~> 3.4.0)
+    rspec-support (3.4.1)
+    rubocop (0.37.2)
+      parser (>= 2.3.0.4, < 3.0)
       powerpack (~> 0.1)
       rainbow (>= 1.99.1, < 3.0)
-      ruby-progressbar (~> 1.4)
+      ruby-progressbar (~> 1.7)
+      unicode-display_width (~> 0.3)
     ruby-progressbar (1.7.5)
-    ruby_parser (3.7.1)
+    ruby_parser (3.7.3)
       sexp_processor (~> 4.1)
-    sexp_processor (4.6.0)
+    sexp_processor (4.6.1)
     shellany (0.0.1)
-    simplecov (0.10.0)
+    simplecov (0.11.2)
       docile (~> 1.1.0)
       json (~> 1.8)
       simplecov-html (~> 0.10.0)
@@ -172,23 +183,22 @@ GEM
     thor (0.19.1)
     thread_safe (0.3.5)
     tins (1.6.0)
-    trema (0.7.1)
-      bundler (~> 1.10.6)
-      gli (~> 2.13.2)
-      phut (~> 0.6.10)
-      pio (~> 0.27.1)
-      rake
+    trema (0.10.0)
+      bundler (~> 1.11.2)
+      gli (~> 2.13.4)
+      phut (~> 0.7.7)
+      pio (~> 0.30.0)
+    tzinfo (1.2.2)
+      thread_safe (~> 0.1)
     unf (0.1.4)
       unf_ext
-    unf_ext (0.0.7.1)
-    unparser (0.2.4)
-      abstract_type (~> 0.0.7)
-      adamantium (~> 0.2.0)
-      concord (~> 0.1.5)
-      diff-lcs (~> 1.2.5)
-      equalizer (~> 0.0.9)
-      parser (~> 2.2.2)
-      procto (~> 0.0.2)
+    unf_ext (0.0.7.2)
+    unicode-display_width (0.3.1)
+    virtus (1.0.5)
+      axiom-types (~> 0.1)
+      coercible (~> 1.0)
+      descendants_tracker (~> 0.0, >= 0.0.3)
+      equalizer (~> 0.0, >= 0.0.9)
     yard (0.8.7.6)
 
 PLATFORMS
@@ -215,4 +225,4 @@ DEPENDENCIES
   yard
 
 BUNDLED WITH
-   1.10.6
+   1.11.2
diff --git a/features/support/hooks.rb b/features/support/hooks.rb
index 391b072..4589898 100644
--- a/features/support/hooks.rb
+++ b/features/support/hooks.rb
@@ -1,5 +1,5 @@
 Before('@sudo') do
-  fail 'sudo authentication failed' unless system 'sudo -v'
+  raise 'sudo authentication failed' unless system 'sudo -v'
   @aruba_timeout_seconds = 5
   ENV['TREMA_LOG_DIR'] = '.'
   ENV['TREMA_PID_DIR'] = '.'
diff --git a/lib/switch_monitor.rb b/lib/switch_monitor.rb
index 2525324..9e60315 100644
--- a/lib/switch_monitor.rb
+++ b/lib/switch_monitor.rb
@@ -19,12 +19,12 @@ def switch_disconnected(dpid)
   end
 
   # rubocop:disable AbcSize
-  def description_stats_reply(dpid, message)
-    logger.info "Switch #{dpid.to_hex} manufacturer = #{message.manufacturer}"
-    logger.info "Switch #{dpid.to_hex} hardware info = #{message.hardware}"
-    logger.info "Switch #{dpid.to_hex} software info = #{message.software}"
-    logger.info "Switch #{dpid.to_hex} serial number = #{message.serial_number}"
-    logger.info "Switch #{dpid.to_hex} description = #{message.datapath}"
+  def description_stats_reply(dpid, desc)
+    logger.info "Switch #{dpid.to_hex} manufacturer = #{desc.manufacturer}"
+    logger.info "Switch #{dpid.to_hex} hardware info = #{desc.hardware}"
+    logger.info "Switch #{dpid.to_hex} software info = #{desc.software}"
+    logger.info "Switch #{dpid.to_hex} serial number = #{desc.serial_number}"
+    logger.info "Switch #{dpid.to_hex} description = #{desc.datapath}"
   end
   # rubocop:enable AbcSize
 
diff --git a/spec/spec_helper.rb b/spec/spec_helper.rb
index 42b551a..a723e39 100644
--- a/spec/spec_helper.rb
+++ b/spec/spec_helper.rb
@@ -8,7 +8,7 @@
   formatters << CodeClimate::TestReporter::Formatter
 end
 
-SimpleCov.formatter = SimpleCov::Formatter::MultiFormatter[*formatters]
+SimpleCov.formatter = SimpleCov::Formatter::MultiFormatter.new(formatters)
 SimpleCov.start { add_filter '/vendor/' }
 
 require 'rspec/given'