diff --git a/rmw_cyclonedds_cpp/src/Serialization.cpp b/rmw_cyclonedds_cpp/src/Serialization.cpp
index 2db412d..8263c58 100644
--- a/rmw_cyclonedds_cpp/src/Serialization.cpp
+++ b/rmw_cyclonedds_cpp/src/Serialization.cpp
@@ -299,8 +299,9 @@ protected:
   void serialize_u32(CDRCursor * cursor, size_t value) const
   {
     assert(value <= std::numeric_limits<uint32_t>::max());
+    auto u32_value = static_cast<uint32_t>(value);
     cursor->align(4);
-    cursor->put_bytes(&value, 4);
+    cursor->put_bytes(&u32_value, 4);
   }
 
   static size_t get_cdr_size_of_primitive(ROSIDL_TypeKind tk)