diff --git a/mrbgems/mruby-io/mrblib/file.rb b/mrbgems/mruby-io/mrblib/file.rb
index 9269ecc7b..a1c62d6d7 100644
--- a/mrbgems/mruby-io/mrblib/file.rb
+++ b/mrbgems/mruby-io/mrblib/file.rb
@@ -104,122 +104,6 @@ class File < IO
     end
   end
 
-  #
-  # call-seq:
-  #   File.directory?(file_name)   -> true or false
-  #
-  # Returns true if the named file is a directory, or a symlink that points at a directory, and false otherwise.
-  #
-  #   File.directory?(".")   #=> true
-  #
-  def self.directory?(file)
-    FileTest.directory?(file)
-  end
-
-  #
-  # call-seq:
-  #   File.exist?(file_name)    -> true or false
-  #
-  # Return true if the named file exists.
-  #
-  #   File.exist?("config.h")      #=> true
-  #   File.exist?("no_such_file")  #=> false
-  #
-  def self.exist?(file)
-    FileTest.exist?(file)
-  end
-
-  #
-  # call-seq:
-  #   File.exists?(file_name)   -> true or false
-  #
-  # Deprecated method that is equivalent to File.exist?.
-  #
-  def self.exists?(file)
-    FileTest.exists?(file)
-  end
-
-  #
-  # call-seq:
-  #   File.file?(file) -> true or false
-  #
-  # Returns true if the named file exists and is a regular file.
-  #
-  #   File.file?("testfile")   #=> true
-  #
-  def self.file?(file)
-    FileTest.file?(file)
-  end
-
-  #
-  # call-seq:
-  #   File.pipe?(file_name)   -> true or false
-  #
-  # Returns true if the named file is a pipe.
-  #
-  #   File.pipe?("/dev/stdin")   #=> true
-  #
-  def self.pipe?(file)
-    FileTest.pipe?(file)
-  end
-
-  #
-  # call-seq:
-  #   File.size(file_name)   -> integer
-  #
-  # Returns the size of file_name.
-  #
-  #   File.size("testfile")   #=> 66
-  #
-  def self.size(file)
-    FileTest.size(file)
-  end
-
-  #
-  # call-seq:
-  #   File.size?(file_name)   -> integer or nil
-  #
-  # Returns nil if file_name doesn't exist or has zero size, the size of the file otherwise.
-  #
-  #   File.size?("testfile")   #=> 66
-  #
-  def self.size?(file)
-    FileTest.size?(file)
-  end
-
-  #
-  # call-seq:
-  #   File.socket?(file_name)   -> true or false
-  #
-  # Returns true if the named file is a socket.
-  #
-  #   File.socket?("/tmp/.X11-unix/X0")   #=> true
-  #
-  def self.socket?(file)
-    FileTest.socket?(file)
-  end
-
-  #
-  # call-seq:
-  #   File.symlink?(file_name)   -> true or false
-  #
-  # Returns true if the named file is a symbolic link.
-  #
-  def self.symlink?(file)
-    FileTest.symlink?(file)
-  end
-
-  #
-  # call-seq:
-  #   File.zero?(file_name)   -> true or false
-  #
-  # Returns true if the named file exists and has a zero size.
-  #
-  #   File.zero?("testfile")   #=> false
-  #
-  def self.zero?(file)
-    FileTest.zero?(file)
-  end
 
 
 end