diff --git a/src/PlainSession.cpp b/src/PlainSession.cpp
index 497768b473cb83982a3df3d9dd85d94dfb4af0f0..6f1a1fcc3ec62aaeb177b2e69fea9c29bd688032 100644
--- a/src/PlainSession.cpp
+++ b/src/PlainSession.cpp
@@ -127,7 +127,7 @@ void PlainSession::startWriteResponse()
 
         ResponseSP response_sp = m_protocolManager_sp->prepareResponse(request_sp);
 
-        boost::uint32_t bodySize = response_sp->ByteSize();
+        boost::uint32_t bodySize = response_sp->ByteSizeLong();
 
         std::vector<boost::uint8_t> writeBuff;
         writeBuff.resize(HEADER_SIZE + bodySize);
@@ -158,4 +158,4 @@ void PlainSession::startWriteResponse()
     }
 }
 
-}   //namespace
\ No newline at end of file
+}   //namespace
diff --git a/src/SSLSession.cpp b/src/SSLSession.cpp
index d1de097dfa8b83ad28d46d0fe82532b08e8b6cee..fd0f33e09bf8ff029de8992125b1f3662870eaaa 100644
--- a/src/SSLSession.cpp
+++ b/src/SSLSession.cpp
@@ -163,7 +163,7 @@ void SSLSession::startWriteResponse()
 
         ResponseSP response_sp = m_protocolManager_sp->prepareResponse(request_sp);
 
-        boost::uint32_t bodySize = response_sp->ByteSize();
+        boost::uint32_t bodySize = response_sp->ByteSizeLong();
 
         std::vector<boost::uint8_t> writeBuff;
         writeBuff.resize(HEADER_SIZE + bodySize);