diff --git a/src/BtBitfieldMessage.cc b/src/BtBitfieldMessage.cc
index 64418a0c..e53cdf85 100644
--- a/src/BtBitfieldMessage.cc
+++ b/src/BtBitfieldMessage.cc
@@ -113,8 +113,6 @@ std::vector<unsigned char> BtBitfieldMessage::createMessage()
   return msg;
 }
 
-size_t BtBitfieldMessage::getMessageLength() { return 5 + bitfieldLength_; }
-
 std::string BtBitfieldMessage::toString() const
 {
   std::string s = NAME;
diff --git a/src/BtBitfieldMessage.h b/src/BtBitfieldMessage.h
index 195b1d1e..0015d439 100644
--- a/src/BtBitfieldMessage.h
+++ b/src/BtBitfieldMessage.h
@@ -68,8 +68,6 @@ public:
 
   virtual std::vector<unsigned char> createMessage() CXX11_OVERRIDE;
 
-  virtual size_t getMessageLength() CXX11_OVERRIDE;
-
   virtual std::string toString() const CXX11_OVERRIDE;
 };
 
diff --git a/src/BtExtendedMessage.cc b/src/BtExtendedMessage.cc
index 10517b3b..9f329c42 100644
--- a/src/BtExtendedMessage.cc
+++ b/src/BtExtendedMessage.cc
@@ -78,14 +78,6 @@ std::vector<unsigned char> BtExtendedMessage::createMessage()
   return msg;
 }
 
-size_t BtExtendedMessage::getMessageLength()
-{
-  if (!msgLength_) {
-    msgLength_ = 6 + extensionMessage_->getPayload().size();
-  }
-  return msgLength_;
-}
-
 bool BtExtendedMessage::sendPredicate() const
 {
   return getPeer()->isExtendedMessagingEnabled();
diff --git a/src/BtExtendedMessage.h b/src/BtExtendedMessage.h
index c22824d1..b61d4dfb 100644
--- a/src/BtExtendedMessage.h
+++ b/src/BtExtendedMessage.h
@@ -63,8 +63,6 @@ public:
 
   virtual std::vector<unsigned char> createMessage() CXX11_OVERRIDE;
 
-  virtual size_t getMessageLength() CXX11_OVERRIDE;
-
   virtual bool sendPredicate() const CXX11_OVERRIDE;
 
   virtual std::string toString() const CXX11_OVERRIDE;
diff --git a/src/BtHandshakeMessage.cc b/src/BtHandshakeMessage.cc
index 7f322f57..ce6023e7 100644
--- a/src/BtHandshakeMessage.cc
+++ b/src/BtHandshakeMessage.cc
@@ -93,8 +93,6 @@ std::vector<unsigned char> BtHandshakeMessage::createMessage()
   return msg;
 }
 
-size_t BtHandshakeMessage::getMessageLength() { return MESSAGE_LENGTH; }
-
 std::string BtHandshakeMessage::toString() const
 {
   return fmt("%s peerId=%s, reserved=%s", NAME,
diff --git a/src/BtHandshakeMessage.h b/src/BtHandshakeMessage.h
index b1a55ad2..3aeeaf11 100644
--- a/src/BtHandshakeMessage.h
+++ b/src/BtHandshakeMessage.h
@@ -81,8 +81,6 @@ public:
 
   virtual std::vector<unsigned char> createMessage() CXX11_OVERRIDE;
 
-  virtual size_t getMessageLength() CXX11_OVERRIDE;
-
   virtual std::string toString() const CXX11_OVERRIDE;
 
   bool isFastExtensionSupported() const;
diff --git a/src/BtKeepAliveMessage.cc b/src/BtKeepAliveMessage.cc
index bf656e46..b2172d7d 100644
--- a/src/BtKeepAliveMessage.cc
+++ b/src/BtKeepAliveMessage.cc
@@ -48,6 +48,4 @@ std::vector<unsigned char> BtKeepAliveMessage::createMessage()
   return std::vector<unsigned char>(MESSAGE_LENGTH);
 }
 
-size_t BtKeepAliveMessage::getMessageLength() { return MESSAGE_LENGTH; }
-
 } // namespace aria2
diff --git a/src/BtKeepAliveMessage.h b/src/BtKeepAliveMessage.h
index 9312b48c..73bf05d8 100644
--- a/src/BtKeepAliveMessage.h
+++ b/src/BtKeepAliveMessage.h
@@ -54,8 +54,6 @@ public:
 
   virtual std::vector<unsigned char> createMessage() CXX11_OVERRIDE;
 
-  virtual size_t getMessageLength() CXX11_OVERRIDE;
-
   virtual std::string toString() const CXX11_OVERRIDE { return NAME; }
 };
 
diff --git a/src/BtPortMessage.cc b/src/BtPortMessage.cc
index 4bc1d957..6a6c8d0f 100644
--- a/src/BtPortMessage.cc
+++ b/src/BtPortMessage.cc
@@ -114,8 +114,6 @@ std::vector<unsigned char> BtPortMessage::createMessage()
   return msg;
 }
 
-size_t BtPortMessage::getMessageLength() { return MESSAGE_LENGTH; }
-
 std::string BtPortMessage::toString() const
 {
   return fmt("%s port=%u", NAME, port_);
diff --git a/src/BtPortMessage.h b/src/BtPortMessage.h
index ede01c00..ded9428b 100644
--- a/src/BtPortMessage.h
+++ b/src/BtPortMessage.h
@@ -73,8 +73,6 @@ public:
 
   virtual std::vector<unsigned char> createMessage() CXX11_OVERRIDE;
 
-  virtual size_t getMessageLength() CXX11_OVERRIDE;
-
   virtual std::string toString() const CXX11_OVERRIDE;
 
   void setLocalNode(DHTNode* localNode);
diff --git a/src/IndexBtMessage.cc b/src/IndexBtMessage.cc
index f71d361d..a31e654d 100644
--- a/src/IndexBtMessage.cc
+++ b/src/IndexBtMessage.cc
@@ -53,8 +53,6 @@ std::vector<unsigned char> IndexBtMessage::createMessage()
   return msg;
 }
 
-size_t IndexBtMessage::getMessageLength() { return MESSAGE_LENGTH; }
-
 std::string IndexBtMessage::toString() const
 {
   return fmt("%s index=%lu", getName(), static_cast<unsigned long>(index_));
diff --git a/src/IndexBtMessage.h b/src/IndexBtMessage.h
index 76f44bac..e4ed881b 100644
--- a/src/IndexBtMessage.h
+++ b/src/IndexBtMessage.h
@@ -67,8 +67,6 @@ public:
 
   virtual std::vector<unsigned char> createMessage() CXX11_OVERRIDE;
 
-  virtual size_t getMessageLength() CXX11_OVERRIDE;
-
   virtual std::string toString() const CXX11_OVERRIDE;
 };
 
diff --git a/src/RangeBtMessage.cc b/src/RangeBtMessage.cc
index 2f811ce7..ffda1801 100644
--- a/src/RangeBtMessage.cc
+++ b/src/RangeBtMessage.cc
@@ -63,8 +63,6 @@ std::vector<unsigned char> RangeBtMessage::createMessage()
   return msg;
 }
 
-size_t RangeBtMessage::getMessageLength() { return MESSAGE_LENGTH; }
-
 std::string RangeBtMessage::toString() const
 {
   return fmt("%s index=%lu, begin=%d, length=%d", getName(),
diff --git a/src/RangeBtMessage.h b/src/RangeBtMessage.h
index 11fd8aa9..73c8f9eb 100644
--- a/src/RangeBtMessage.h
+++ b/src/RangeBtMessage.h
@@ -77,8 +77,6 @@ public:
 
   virtual std::vector<unsigned char> createMessage() CXX11_OVERRIDE;
 
-  virtual size_t getMessageLength() CXX11_OVERRIDE;
-
   virtual std::string toString() const CXX11_OVERRIDE;
 };
 
diff --git a/src/SimpleBtMessage.cc b/src/SimpleBtMessage.cc
index 57bc5aa2..92f1a8a8 100644
--- a/src/SimpleBtMessage.cc
+++ b/src/SimpleBtMessage.cc
@@ -57,7 +57,6 @@ void SimpleBtMessage::send()
                   getPeer()->getIPAddress().c_str(), getPeer()->getPort(),
                   toString().c_str()));
   auto msg = createMessage();
-  size_t msgLength = getMessageLength();
   A2_LOG_DEBUG(
       fmt("msglength = %lu bytes", static_cast<unsigned long>(msg.size())));
   getPeerConnection()->pushBytes(std::move(msg), getProgressUpdate());
diff --git a/src/SimpleBtMessage.h b/src/SimpleBtMessage.h
index c1398149..76331682 100644
--- a/src/SimpleBtMessage.h
+++ b/src/SimpleBtMessage.h
@@ -51,8 +51,6 @@ public:
 
   virtual std::vector<unsigned char> createMessage() = 0;
 
-  virtual size_t getMessageLength() = 0;
-
   virtual std::unique_ptr<ProgressUpdate> getProgressUpdate();
 
   virtual bool sendPredicate() const { return true; };
diff --git a/src/ZeroBtMessage.cc b/src/ZeroBtMessage.cc
index d5641b06..dbe10f94 100644
--- a/src/ZeroBtMessage.cc
+++ b/src/ZeroBtMessage.cc
@@ -54,8 +54,6 @@ std::vector<unsigned char> ZeroBtMessage::createMessage()
   return msg;
 }
 
-size_t ZeroBtMessage::getMessageLength() { return MESSAGE_LENGTH; }
-
 std::string ZeroBtMessage::toString() const { return getName(); }
 
 } // namespace aria2
diff --git a/src/ZeroBtMessage.h b/src/ZeroBtMessage.h
index 875fd166..8afd3334 100644
--- a/src/ZeroBtMessage.h
+++ b/src/ZeroBtMessage.h
@@ -58,8 +58,6 @@ public:
 
   virtual std::vector<unsigned char> createMessage() CXX11_OVERRIDE;
 
-  virtual size_t getMessageLength() CXX11_OVERRIDE;
-
   virtual std::string toString() const CXX11_OVERRIDE;
 };
 
diff --git a/test/BtBitfieldMessageTest.cc b/test/BtBitfieldMessageTest.cc
index f4b248fe..90b07810 100644
--- a/test/BtBitfieldMessageTest.cc
+++ b/test/BtBitfieldMessageTest.cc
@@ -79,7 +79,6 @@ void BtBitfieldMessageTest::testCreateMessage()
   auto rawmsg = msg.createMessage();
   CPPUNIT_ASSERT_EQUAL((size_t)7, rawmsg.size());
   CPPUNIT_ASSERT(std::equal(std::begin(rawmsg), std::end(rawmsg), data));
-  CPPUNIT_ASSERT_EQUAL((size_t)7, msg.getMessageLength());
 }
 
 void BtBitfieldMessageTest::testDoReceivedAction()
diff --git a/test/BtExtendedMessageTest.cc b/test/BtExtendedMessageTest.cc
index 5e7d4ca6..f32f3426 100644
--- a/test/BtExtendedMessageTest.cc
+++ b/test/BtExtendedMessageTest.cc
@@ -81,7 +81,6 @@ void BtExtendedMessageTest::testCreateMessage()
   auto rawmsg = msg.createMessage();
   CPPUNIT_ASSERT_EQUAL((size_t)17, rawmsg.size());
   CPPUNIT_ASSERT(std::equal(std::begin(rawmsg), std::end(rawmsg), data));
-  CPPUNIT_ASSERT_EQUAL((size_t)17, msg.getMessageLength());
 }
 
 void BtExtendedMessageTest::testDoReceivedAction()
diff --git a/test/BtKeepAliveMessageTest.cc b/test/BtKeepAliveMessageTest.cc
index 36d2eb59..2d9d4872 100644
--- a/test/BtKeepAliveMessageTest.cc
+++ b/test/BtKeepAliveMessageTest.cc
@@ -27,7 +27,6 @@ void BtKeepAliveMessageTest::testCreateMessage()
   memset(data, 0, sizeof(data));
   BtKeepAliveMessage message;
   CPPUNIT_ASSERT_EQUAL((uint8_t)99, message.getId());
-  CPPUNIT_ASSERT_EQUAL((size_t)4, message.getMessageLength());
   auto rawmsg = message.createMessage();
   CPPUNIT_ASSERT_EQUAL((size_t)4, rawmsg.size());
   CPPUNIT_ASSERT(std::equal(std::begin(rawmsg), std::end(rawmsg), data));