diff --git a/lib/mruby/build/command.rb b/lib/mruby/build/command.rb
index d34e4e409..970264407 100644
--- a/lib/mruby/build/command.rb
+++ b/lib/mruby/build/command.rb
@@ -317,7 +317,7 @@ module MRuby
     end
 
     def commit_hash(dir)
-      `#{@command} --git-dir #{shellquote(dir +'/.git')} --work-tree #{shellquote(dir)} rev-parse --verify HEAD`.strip
+      `#{@command} --git-dir #{shellquote(dir + '/.git')} --work-tree #{shellquote(dir)} rev-parse --verify HEAD`.strip
     end
 
     def current_branch(dir)
diff --git a/lib/mruby/gem.rb b/lib/mruby/gem.rb
index a2b649d71..619621e7b 100644
--- a/lib/mruby/gem.rb
+++ b/lib/mruby/gem.rb
@@ -465,8 +465,8 @@ module MRuby
         table.instance_variable_set :@root_gems, ary
         class << table
           include TSort
-          def tsort_each_node &b
-            @root_gems.each &b
+          def tsort_each_node(&b)
+            @root_gems.each(&b)
           end
 
           def tsort_each_child(n, &b)