diff --git a/lib/concurrent.rb b/lib/concurrent.rb
index d6a9061e8..f2a8ce645 100644
--- a/lib/concurrent.rb
+++ b/lib/concurrent.rb
@@ -9,7 +9,6 @@
 require 'concurrent/errors'
 require 'concurrent/executors'
 require 'concurrent/utilities'
-require 'concurrent/struct'
 
 require 'concurrent/atomic/atomic_reference'
 require 'concurrent/atom'
@@ -17,11 +16,14 @@
 require 'concurrent/dataflow'
 require 'concurrent/delay'
 require 'concurrent/future'
+require 'concurrent/immutable_struct'
 require 'concurrent/ivar'
 require 'concurrent/maybe'
+require 'concurrent/mutable_struct'
 require 'concurrent/mvar'
 require 'concurrent/promise'
 require 'concurrent/scheduled_task'
+require 'concurrent/settable_struct'
 require 'concurrent/timer_task'
 require 'concurrent/tvar'
 
diff --git a/lib/concurrent/struct/immutable_struct.rb b/lib/concurrent/immutable_struct.rb
similarity index 88%
rename from lib/concurrent/struct/immutable_struct.rb
rename to lib/concurrent/immutable_struct.rb
index 9eaf308b4..ee0591a45 100644
--- a/lib/concurrent/struct/immutable_struct.rb
+++ b/lib/concurrent/immutable_struct.rb
@@ -1,4 +1,4 @@
-require 'concurrent/struct/abstract_struct'
+require 'concurrent/synchronization/abstract_struct'
 require 'concurrent/synchronization'
 
 module Concurrent
@@ -7,7 +7,7 @@ module Concurrent
   #
   # @see http://ruby-doc.org/core-2.2.0/Struct.html Ruby standard library `Struct`
   module ImmutableStruct
-    include AbstractStruct
+    include Synchronization::AbstractStruct
 
     # @!macro struct_values
     def values
@@ -80,7 +80,7 @@ def self.new(*args, &block)
     FACTORY = Class.new(Synchronization::Object) do
       def define_struct(name, members, &block)
         synchronize do
-          AbstractStruct.define_struct_class(ImmutableStruct, Synchronization::Object, name, members, &block)
+          Synchronization::AbstractStruct.define_struct_class(ImmutableStruct, Synchronization::Object, name, members, &block)
         end
       end
     end.new
diff --git a/lib/concurrent/struct/mutable_struct.rb b/lib/concurrent/mutable_struct.rb
similarity index 96%
rename from lib/concurrent/struct/mutable_struct.rb
rename to lib/concurrent/mutable_struct.rb
index 9c3efa6bb..68b0040d4 100644
--- a/lib/concurrent/struct/mutable_struct.rb
+++ b/lib/concurrent/mutable_struct.rb
@@ -1,4 +1,4 @@
-require 'concurrent/struct/abstract_struct'
+require 'concurrent/synchronization/abstract_struct'
 require 'concurrent/synchronization'
 
 module Concurrent
@@ -8,7 +8,7 @@ module Concurrent
   #
   # @see http://ruby-doc.org/core-2.2.0/Struct.html Ruby standard library `Struct`
   module MutableStruct
-    include AbstractStruct
+    include Synchronization::AbstractStruct
 
     # @!macro [new] struct_new
     #
@@ -88,7 +88,7 @@ def inspect
     #   @yieldparam [Object] selfvalue the value of the member in `self`
     #   @yieldparam [Object] othervalue the value of the member in `other`
     #
-    #   @return [AbstractStruct] a new struct with the new values
+    #   @return [Synchronization::AbstractStruct] a new struct with the new values
     #
     #   @raise [ArgumentError] of given a member that is not defined in the struct
     def merge(other, &block)
@@ -209,7 +209,7 @@ def self.new(*args, &block)
     FACTORY = Class.new(Synchronization::Object) do
       def define_struct(name, members, &block)
         synchronize do
-          clazz = AbstractStruct.define_struct_class(MutableStruct, Synchronization::Object, name, members, &block)
+          clazz = Synchronization::AbstractStruct.define_struct_class(MutableStruct, Synchronization::Object, name, members, &block)
           members.each_with_index do |member, index|
             clazz.send(:define_method, member) do
               synchronize { @values[index] }
diff --git a/lib/concurrent/struct/settable_struct.rb b/lib/concurrent/settable_struct.rb
similarity index 93%
rename from lib/concurrent/struct/settable_struct.rb
rename to lib/concurrent/settable_struct.rb
index 09fe705b8..f0b397a72 100644
--- a/lib/concurrent/struct/settable_struct.rb
+++ b/lib/concurrent/settable_struct.rb
@@ -1,4 +1,4 @@
-require 'concurrent/struct/abstract_struct'
+require 'concurrent/synchronization/abstract_struct'
 require 'concurrent/errors'
 require 'concurrent/synchronization'
 
@@ -12,7 +12,7 @@ module Concurrent
   # @see http://ruby-doc.org/core-2.2.0/Struct.html Ruby standard library `Struct`
   # @see http://en.wikipedia.org/wiki/Final_(Java) Java `final` keyword
   module SettableStruct
-    include AbstractStruct
+    include Synchronization::AbstractStruct
 
     # @!macro struct_values
     def values
@@ -104,7 +104,7 @@ def self.new(*args, &block)
     FACTORY = Class.new(Synchronization::Object) do
       def define_struct(name, members, &block)
         synchronize do
-          clazz = AbstractStruct.define_struct_class(SettableStruct, Synchronization::Object, name, members, &block)
+          clazz = Synchronization::AbstractStruct.define_struct_class(SettableStruct, Synchronization::Object, name, members, &block)
           members.each_with_index do |member, index|
             clazz.send(:define_method, member) do
               synchronize { @values[index] }
diff --git a/lib/concurrent/struct.rb b/lib/concurrent/struct.rb
deleted file mode 100644
index 6aacba684..000000000
--- a/lib/concurrent/struct.rb
+++ /dev/null
@@ -1,3 +0,0 @@
-require 'concurrent/struct/immutable_struct'
-require 'concurrent/struct/mutable_struct'
-require 'concurrent/struct/settable_struct'
diff --git a/lib/concurrent/struct/abstract_struct.rb b/lib/concurrent/struct/abstract_struct.rb
deleted file mode 100644
index 755940feb..000000000
--- a/lib/concurrent/struct/abstract_struct.rb
+++ /dev/null
@@ -1,155 +0,0 @@
-module Concurrent
-
-  # @!visibility private
-  module AbstractStruct
-
-    # @!visibility private
-    def initialize(*values)
-      super()
-      ns_initialize(*values)
-      ensure_ivar_visibility!
-    end
-
-    # @!macro [attach] struct_length
-    #
-    #   Returns the number of struct members.
-    #
-    #   @return [Fixnum] the number of struct members
-    def length
-      self.class::MEMBERS.length
-    end
-    alias_method :size, :length
-
-    # @!macro [attach] struct_members
-    #
-    #   Returns the struct members as an array of symbols.
-    #
-    #   @return [Array] the struct members as an array of symbols
-    def members
-      self.class::MEMBERS.dup
-    end
-
-    protected
-
-    # @!macro struct_values
-    #
-    # @!visibility private
-    def ns_values
-      @values.dup
-    end
-
-    # @!macro struct_values_at
-    #
-    # @!visibility private
-    def ns_values_at(indexes)
-      @values.values_at(*indexes)
-    end
-
-    # @!macro struct_to_h
-    #
-    # @!visibility private
-    def ns_to_h
-      length.times.reduce({}){|memo, i| memo[self.class::MEMBERS[i]] = @values[i]; memo}
-    end
-
-    # @!macro struct_get
-    #
-    # @!visibility private
-    def ns_get(member)
-      if member.is_a? Integer
-        if member >= @values.length
-          raise IndexError.new("offset #{member} too large for struct(size:#{@values.length})")
-        end
-        @values[member]
-      else
-        send(member)
-      end
-    rescue NoMethodError
-      raise NameError.new("no member '#{member}' in struct")
-    end
-
-    # @!macro struct_equality
-    #
-    # @!visibility private
-    def ns_equality(other)
-      self.class == other.class && self.values == other.values
-    end
-
-    # @!macro struct_each
-    #
-    # @!visibility private
-    def ns_each
-      values.each{|value| yield value }
-    end
-
-    # @!macro struct_each_pair
-    #
-    # @!visibility private
-    def ns_each_pair
-      @values.length.times do |index|
-        yield self.class::MEMBERS[index], @values[index]
-      end
-    end
-
-    # @!macro struct_select
-    #
-    # @!visibility private
-    def ns_select
-      values.select{|value| yield value }
-    end
-
-    # @!macro struct_inspect
-    #
-    # @!visibility private
-    def ns_inspect
-      struct = pr_underscore(self.class.ancestors[1])
-      clazz = ((self.class.to_s =~ /^#<Class:/) == 0) ? '' : " #{self.class}"
-      "#<#{struct}#{clazz} #{ns_to_h}>"
-    end
-
-    # @!macro struct_merge
-    #
-    # @!visibility private
-    def ns_merge(other, &block)
-      self.class.new(*self.to_h.merge(other, &block).values)
-    end
-
-    # @!visibility private
-    def pr_underscore(clazz)
-      word = clazz.to_s
-      word.gsub!(/::/, '/')
-      word.gsub!(/([A-Z]+)([A-Z][a-z])/,'\1_\2')
-      word.gsub!(/([a-z\d])([A-Z])/,'\1_\2')
-      word.tr!("-", "_")
-      word.downcase!
-      word
-    end
-
-    # @!visibility private
-    def self.define_struct_class(parent, base, name, members, &block)
-      clazz = Class.new(base || Object) do
-        include parent
-        self.const_set(:MEMBERS, members.collect{|member| member.to_s.to_sym}.freeze) 
-        def ns_initialize(*values)
-          raise ArgumentError.new('struct size differs') if values.length > length
-          @values = values.fill(nil, values.length..length-1)
-        end
-      end
-      unless name.nil?
-        begin
-          parent.const_set(name, clazz)
-          parent.const_get(name)
-        rescue NameError
-          raise NameError.new("identifier #{name} needs to be constant") 
-        end
-      end
-      members.each_with_index do |member, index|
-        clazz.send(:define_method, member) do
-          @values[index]
-        end
-      end
-      clazz.class_exec(&block) unless block.nil?
-      clazz
-    end
-  end
-end
diff --git a/lib/concurrent/synchronization/abstract_struct.rb b/lib/concurrent/synchronization/abstract_struct.rb
new file mode 100644
index 000000000..480383f93
--- /dev/null
+++ b/lib/concurrent/synchronization/abstract_struct.rb
@@ -0,0 +1,157 @@
+module Concurrent
+  module Synchronization
+
+    # @!visibility private
+    module AbstractStruct
+
+      # @!visibility private
+      def initialize(*values)
+        super()
+        ns_initialize(*values)
+        ensure_ivar_visibility!
+      end
+
+      # @!macro [attach] struct_length
+      #
+      #   Returns the number of struct members.
+      #
+      #   @return [Fixnum] the number of struct members
+      def length
+        self.class::MEMBERS.length
+      end
+      alias_method :size, :length
+
+      # @!macro [attach] struct_members
+      #
+      #   Returns the struct members as an array of symbols.
+      #
+      #   @return [Array] the struct members as an array of symbols
+      def members
+        self.class::MEMBERS.dup
+      end
+
+      protected
+
+      # @!macro struct_values
+      #
+      # @!visibility private
+      def ns_values
+        @values.dup
+      end
+
+      # @!macro struct_values_at
+      #
+      # @!visibility private
+      def ns_values_at(indexes)
+        @values.values_at(*indexes)
+      end
+
+      # @!macro struct_to_h
+      #
+      # @!visibility private
+      def ns_to_h
+        length.times.reduce({}){|memo, i| memo[self.class::MEMBERS[i]] = @values[i]; memo}
+      end
+
+      # @!macro struct_get
+      #
+      # @!visibility private
+      def ns_get(member)
+        if member.is_a? Integer
+          if member >= @values.length
+            raise IndexError.new("offset #{member} too large for struct(size:#{@values.length})")
+          end
+          @values[member]
+        else
+          send(member)
+        end
+      rescue NoMethodError
+        raise NameError.new("no member '#{member}' in struct")
+      end
+
+      # @!macro struct_equality
+      #
+      # @!visibility private
+      def ns_equality(other)
+        self.class == other.class && self.values == other.values
+      end
+
+      # @!macro struct_each
+      #
+      # @!visibility private
+      def ns_each
+        values.each{|value| yield value }
+      end
+
+      # @!macro struct_each_pair
+      #
+      # @!visibility private
+      def ns_each_pair
+        @values.length.times do |index|
+          yield self.class::MEMBERS[index], @values[index]
+        end
+      end
+
+      # @!macro struct_select
+      #
+      # @!visibility private
+      def ns_select
+        values.select{|value| yield value }
+      end
+
+      # @!macro struct_inspect
+      #
+      # @!visibility private
+      def ns_inspect
+        struct = pr_underscore(self.class.ancestors[1])
+        clazz = ((self.class.to_s =~ /^#<Class:/) == 0) ? '' : " #{self.class}"
+        "#<#{struct}#{clazz} #{ns_to_h}>"
+      end
+
+      # @!macro struct_merge
+      #
+      # @!visibility private
+      def ns_merge(other, &block)
+        self.class.new(*self.to_h.merge(other, &block).values)
+      end
+
+      # @!visibility private
+      def pr_underscore(clazz)
+        word = clazz.to_s
+        word.gsub!(/::/, '/')
+        word.gsub!(/([A-Z]+)([A-Z][a-z])/,'\1_\2')
+        word.gsub!(/([a-z\d])([A-Z])/,'\1_\2')
+        word.tr!("-", "_")
+        word.downcase!
+        word
+      end
+
+      # @!visibility private
+      def self.define_struct_class(parent, base, name, members, &block)
+        clazz = Class.new(base || Object) do
+          include parent
+          self.const_set(:MEMBERS, members.collect{|member| member.to_s.to_sym}.freeze) 
+          def ns_initialize(*values)
+            raise ArgumentError.new('struct size differs') if values.length > length
+            @values = values.fill(nil, values.length..length-1)
+          end
+        end
+        unless name.nil?
+          begin
+            parent.const_set(name, clazz)
+            parent.const_get(name)
+          rescue NameError
+            raise NameError.new("identifier #{name} needs to be constant") 
+          end
+        end
+        members.each_with_index do |member, index|
+          clazz.send(:define_method, member) do
+            @values[index]
+          end
+        end
+        clazz.class_exec(&block) unless block.nil?
+        clazz
+      end
+    end
+  end
+end
diff --git a/spec/concurrent/struct/immutable_struct_spec.rb b/spec/concurrent/immutable_struct_spec.rb
similarity index 100%
rename from spec/concurrent/struct/immutable_struct_spec.rb
rename to spec/concurrent/immutable_struct_spec.rb
diff --git a/spec/concurrent/struct/mutable_struct_spec.rb b/spec/concurrent/mutable_struct_spec.rb
similarity index 100%
rename from spec/concurrent/struct/mutable_struct_spec.rb
rename to spec/concurrent/mutable_struct_spec.rb
diff --git a/spec/concurrent/struct/settable_struct_spec.rb b/spec/concurrent/settable_struct_spec.rb
similarity index 100%
rename from spec/concurrent/struct/settable_struct_spec.rb
rename to spec/concurrent/settable_struct_spec.rb
diff --git a/spec/concurrent/struct/struct_shared.rb b/spec/concurrent/struct_shared.rb
similarity index 100%
rename from spec/concurrent/struct/struct_shared.rb
rename to spec/concurrent/struct_shared.rb