diff --git a/rmw_cyclonedds_cpp/src/serdes.cpp b/rmw_cyclonedds_cpp/src/serdes.cpp
index 51a4723..d5857aa 100755
--- a/rmw_cyclonedds_cpp/src/serdes.cpp
+++ b/rmw_cyclonedds_cpp/src/serdes.cpp
@@ -32,10 +32,10 @@ cycser::cycser(std::vector<unsigned char> & dst_)
   dst.push_back(0);
 }
 
-cycdeserbase::cycdeserbase(const char * data_, size_t lim_)
+cycdeserbase::cycdeserbase(const char * data_, size_t size_)
 : data(data_),
   pos(0),
-  lim(lim_),
+  lim(size_),
   swap_bytes(false)
 {
   /* Get the endianness byte (skip unused first byte in data[0]) */
@@ -46,17 +46,17 @@ cycdeserbase::cycdeserbase(const char * data_, size_t lim_)
 
   /* Ignore representation options (data_[2] and data_[3]) */
   data += 4;
+  lim -= 4;
 }
 
 cycdeser::cycdeser(const void * data_, size_t size_)
-: cycdeserbase(static_cast<const char *>(data_), size_ - 4)
+: cycdeserbase(static_cast<const char *>(data_), size_)
 {
 }
 
 cycprint::cycprint(char * buf_, size_t bufsize_, const void * data_, size_t size_)
-: cycdeserbase(static_cast<const char *>(data_), size_ - 4),
+: cycdeserbase(static_cast<const char *>(data_), size_),
   buf(buf_),
   bufsize(bufsize_)
 {
-  static_cast<void>(size_);
 }