diff --git a/mrbgems/mruby-struct/mrblib/struct.rb b/mrbgems/mruby-struct/mrblib/struct.rb
index 7599be970..aa8e3f8a6 100644
--- a/mrbgems/mruby-struct/mrblib/struct.rb
+++ b/mrbgems/mruby-struct/mrblib/struct.rb
@@ -11,7 +11,7 @@ class Struct
   #
   # ISO 15.2.18.4.4
   def each(&block)
-    self.class.members.each{|field|
+    self.class.members.each {|field|
       block.call(self[field])
     }
     self
@@ -24,7 +24,7 @@ class Struct
   #
   # ISO 15.2.18.4.5
   def each_pair(&block)
-    self.class.members.each{|field|
+    self.class.members.each {|field|
       block.call(field.to_sym, self[field])
     }
     self
@@ -38,7 +38,7 @@ class Struct
   # ISO 15.2.18.4.7
   def select(&block)
     ary = []
-    self.class.members.each{|field|
+    self.class.members.each {|field|
       val = self[field]
       ary.push(val) if block.call(val)
     }