diff --git a/lib/cpp/src/transport/TTransportUtils.cpp b/lib/cpp/src/transport/TTransportUtils.cpp
index 02454e3..9367eb5 100644
--- a/lib/cpp/src/transport/TTransportUtils.cpp
+++ b/lib/cpp/src/transport/TTransportUtils.cpp
@@ -164,7 +164,7 @@
   transport_->write((const uint8_t*)&sz, 4);
   
   // Write frame body
-  if (sz > 0) {
+  if (wLen_ > 0) {
     transport_->write(wBuf_, wLen_);
   }