diff --git a/src/j3/Phttpd.java b/src/j3/Phttpd.java
index 137c98e..b529748 100644
--- a/src/j3/Phttpd.java
+++ b/src/j3/Phttpd.java
@@ -6,10 +6,10 @@
 
 // ライブラリの利用
 import java.io.BufferedReader;
+import java.io.DataOutputStream;
 import java.io.FileInputStream;
 import java.io.IOException;
 import java.io.InputStreamReader;
-import java.io.OutputStream;
 import java.net.ServerSocket;
 import java.net.Socket;
 
@@ -21,7 +21,7 @@
 		Socket sock ;
 
 		// 入出力
-		OutputStream out ;
+		DataOutputStream dout;
 		BufferedReader in ;
 		FileInputStream infile = null;
 		byte[] buff = new byte[1024];
@@ -50,7 +50,7 @@
 				// 読み書き用オブジェクトの生成
 				in = new BufferedReader(new
 				InputStreamReader(sock.getInputStream()));
-				out = sock.getOutputStream() ;
+				dout = new DataOutputStream(sock.getOutputStream() );
 				// とりあえず改行を２つ読み飛ばす
 				for(i = 0; i < 2;++i)
 					System.out.println(in.readLine() );
@@ -61,7 +61,7 @@
 					try{
 						int n = infile.read(buff);
 						System.out.write(buff, 0, n);
-						out.write(buff,0,n) ;
+						dout.write(buff,0,n) ;
 					}
 					catch(Exception e){
 						cont = false ;