diff --git a/src/BtConstants.h b/src/BtConstants.h
index 16736847..c6b3e51b 100644
--- a/src/BtConstants.h
+++ b/src/BtConstants.h
@@ -46,7 +46,7 @@ constexpr size_t PIECE_HASH_LENGTH = 20;
 
 constexpr size_t PEER_ID_LENGTH = 20;
 
-constexpr size_t MAX_BLOCK_LENGTH = 32_k;
+constexpr size_t MAX_BLOCK_LENGTH = 64_k;
 
 constexpr size_t DEFAULT_MAX_OUTSTANDING_REQUEST = 6;
 
diff --git a/test/BtRequestMessageTest.cc b/test/BtRequestMessageTest.cc
index 1d3841cc..2177cef8 100644
--- a/test/BtRequestMessageTest.cc
+++ b/test/BtRequestMessageTest.cc
@@ -266,7 +266,7 @@ void BtRequestMessageTest::testValidate()
 
 void BtRequestMessageTest::testValidate_lengthTooLong()
 {
-  BtRequestMessage msg(0, 0, 32_k + 1);
+  BtRequestMessage msg(0, 0, MAX_BLOCK_LENGTH + 1);
   msg.setBtMessageValidator(
       make_unique<RangeBtMessageValidator>(&msg, 1_k, 256_k));
   try {
@@ -274,7 +274,9 @@ void BtRequestMessageTest::testValidate_lengthTooLong()
     CPPUNIT_FAIL("exception must be thrown.");
   }
   catch (DlAbortEx& e) {
-    CPPUNIT_ASSERT_EQUAL(std::string("Length too long: 32769 > 32KB"),
+    CPPUNIT_ASSERT_EQUAL("Length too long: " +
+                             util::uitos(MAX_BLOCK_LENGTH + 1) + " > " +
+                             util::uitos(MAX_BLOCK_LENGTH / 1024) + "KB",
                          std::string(e.what()));
   }
 }
diff --git a/test/PeerConnectionTest.cc b/test/PeerConnectionTest.cc
index f1d8374d..feb0f570 100644
--- a/test/PeerConnectionTest.cc
+++ b/test/PeerConnectionTest.cc
@@ -28,7 +28,7 @@ void PeerConnectionTest::testReserveBuffer()
   CPPUNIT_ASSERT_EQUAL((size_t)MAX_BUFFER_CAPACITY, con.getBufferCapacity());
   CPPUNIT_ASSERT_EQUAL((size_t)3, con.getBufferLength());
 
-  constexpr size_t newLength = 64_k;
+  constexpr size_t newLength = 128_k;
   con.reserveBuffer(newLength);
 
   CPPUNIT_ASSERT_EQUAL(newLength, con.getBufferCapacity());