diff --git a/mrbgems/mruby-set/.travis.yml b/mrbgems/mruby-set/.travis.yml
index 4cb8c743f..e438907a6 100644
--- a/mrbgems/mruby-set/.travis.yml
+++ b/mrbgems/mruby-set/.travis.yml
@@ -10,5 +10,5 @@ language: c
 compiler:
   - gcc
   - clang
-script: 
+script:
   - rake test
diff --git a/mrbgems/mruby-set/LICENSE b/mrbgems/mruby-set/LICENSE
index c88fed237..d892b29f6 100644
--- a/mrbgems/mruby-set/LICENSE
+++ b/mrbgems/mruby-set/LICENSE
@@ -22,4 +22,3 @@ TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
 SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 
 [ MIT license: http://www.opensource.org/licenses/mit-license.php ]
-
diff --git a/mrbgems/mruby-set/README.md b/mrbgems/mruby-set/README.md
index 616bd3e28..fb9592b90 100644
--- a/mrbgems/mruby-set/README.md
+++ b/mrbgems/mruby-set/README.md
@@ -2,9 +2,9 @@
 
 Set class
 
-## install by mrbgems 
+## install by mrbgems
 
-- add conf.gem line to `build_config.rb` 
+- add conf.gem line to `build_config.rb`
 
 ```ruby
 MRuby::Build.new do |conf|
@@ -15,7 +15,7 @@ MRuby::Build.new do |conf|
 end
 ```
 
-## example 
+## example
 
 ```ruby
 set1 = Set.new([1,2])
@@ -36,12 +36,14 @@ set1 ^ set2
 
 These methods are not implemented yet.
 
-+ freeze
-+ taint
-+ untaint
-+ to_set
-+ divide(Set#divide with 2 arity block is not implemented.)
+- freeze
+- taint
+- untaint
+- to_set
+- divide(Set#divide with 2 arity block is not implemented.)
 
 ## License
+
 under the MIT License:
+
 - see LICENSE file
diff --git a/mrbgems/mruby-set/test/mrb_set.rb b/mrbgems/mruby-set/test/mrb_set.rb
index d8c838178..dccb90ec9 100644
--- a/mrbgems/mruby-set/test/mrb_set.rb
+++ b/mrbgems/mruby-set/test/mrb_set.rb
@@ -1,4 +1,4 @@
-##  
+##
 ## Set Test
 ##
 
@@ -367,7 +367,7 @@ assert("Set#each") do
       ary.delete(o) or raise "unexpected element: #{o}"
     }
     ary.empty? or raise "forgotten elements: #{ary.join(', ')}"
-  }  
+  }
 end
 
 assert("Set#add") do
@@ -514,7 +514,7 @@ assert("Set#-") do
 
   ret = set - [2,4,6]
   assert_false set.equal?(ret) # assert_not_same
-  assert_equal(Set[1,3], ret)  
+  assert_equal(Set[1,3], ret)
 end
 
 assert("Set#&") do
@@ -522,7 +522,7 @@ assert("Set#&") do
 
   ret = set & [2,4,6]
   assert_false set.equal?(ret) # assert_not_same
-  assert_equal(Set[2,4], ret)  
+  assert_equal(Set[2,4], ret)
 end
 
 assert("Set#^") do
@@ -530,7 +530,7 @@ assert("Set#^") do
 
   ret = set ^ [2,4,5,5]
   assert_false set.equal?(ret) # assert_not_same
-  assert_equal(Set[1,3,5], ret)  
+  assert_equal(Set[1,3,5], ret)
 end
 
 assert("Set#==") do