diff --git a/.rubocop.yml b/.rubocop.yml
index 0eaf834..4c154f6 100644
--- a/.rubocop.yml
+++ b/.rubocop.yml
@@ -1,3 +1,6 @@
+AllCops:
+  TargetRubyVersion: 2.0
+
 Style/Documentation:
   Enabled: false
 
@@ -7,5 +10,25 @@ Style/FileName:
 Style/Semicolon:
   AllowAsExpressionSeparator: true
 
-Style/TrailingComma:
+Style/TrailingCommaInLiteral:
   EnforcedStyleForMultiline: comma
+
+Style/TrailingCommaInArguments:
+  EnforcedStyleForMultiline: comma
+
+Style/SignalException:
+  EnforcedStyle: semantic
+
+Style/ClassAndModuleChildren:
+  EnforcedStyle: compact
+
+Style/TrivialAccessors:
+  AllowPredicates: true
+
+Style/Alias:
+  EnforcedStyle: prefer_alias_method
+
+Lint/ShadowingOuterLocalVariable:
+  Exclude:
+    - examples/many_to_one.rb
+    - examples/one_to_many.rb
diff --git a/examples/many_to_one.rb b/examples/many_to_one.rb
index 22789a0..257b627 100644
--- a/examples/many_to_one.rb
+++ b/examples/many_to_one.rb
@@ -5,11 +5,11 @@ require 'channel'
 c = Channel.new
 
 1.upto(5) do |i|
-  go(lambda { |i, co|
+  go(lambda do |i, co|
     1.upto(5) do |j|
-        co << format("hi from %d.%d", i, j)
+      co << format('hi from %d.%d', i, j)
     end
-  }, i, c)
+  end, i, c)
 end
 
 25.times { puts c.recv }
diff --git a/examples/non_blocking_channel_operations.rb b/examples/non_blocking_channel_operations.rb
index dadf5be..3e9a207 100644
--- a/examples/non_blocking_channel_operations.rb
+++ b/examples/non_blocking_channel_operations.rb
@@ -12,14 +12,14 @@ Channel.select(messages) do |msg, c|
   end
 end
 
-msg = 'hi'
-messages <- msg
-#select {
-#case messages <- msg:
-#    fmt.Println("sent message", msg)
-#default:
-#    fmt.Println("no message sent")
-#}
+# msg = 'hi'
+# messages <- msg
+# select {
+# case messages <- msg:
+#     fmt.Println("sent message", msg)
+# default:
+#     fmt.Println("no message sent")
+# }
 
 Channel.select(messages, signals) do |res, c|
   case c
diff --git a/examples/one_to_many.rb b/examples/one_to_many.rb
index fb25daf..4331ad4 100644
--- a/examples/one_to_many.rb
+++ b/examples/one_to_many.rb
@@ -8,15 +8,15 @@ w = WaitGroup.new
 w.add(5)
 
 1.upto(5) do |i|
-  go(lambda { |i, ci|
-      j = 1
-      ci.each { |v|
-        sleep(0.001)
-        puts format("%d.%d got %d", i, j, v)
-        j += 1
-      }
-      w.done
-  }, i, c)
+  go(lambda do |i, ci|
+    j = 1
+    ci.each do |v|
+      sleep(0.001)
+      puts format('%d.%d got %d', i, j, v)
+      j += 1
+    end
+    w.done
+  end, i, c)
 end
 
 1.upto(25) { |i| c << i }
diff --git a/test/test_channel.rb b/test/test_channel.rb
index 1254789..c3c1b26 100644
--- a/test/test_channel.rb
+++ b/test/test_channel.rb
@@ -8,9 +8,9 @@ require 'channel'
 
 class TestChannel < Test::Unit::TestCase
   module Util
-    def meanwhile(*procs, &blk)
+    def meanwhile(*procs)
       threads = procs.map { |p| Thread.new(&p) }
-      blk.call
+      yield
       threads.each(&:join)
     end
   end
diff --git a/test/test_waitgroup.rb b/test/test_waitgroup.rb
index b05922f..822f646 100644
--- a/test/test_waitgroup.rb
+++ b/test/test_waitgroup.rb
@@ -7,9 +7,9 @@ require 'channel/waitgroup'
 
 class TestWaitGroup < Test::Unit::TestCase
   module Util
-    def meanwhile(*procs, &blk)
+    def meanwhile(*procs)
       threads = procs.map { |p| Thread.new(&p) }
-      blk.call
+      yield
       threads.each(&:join)
     end
   end