diff --git a/libuavcan/include/uavcan/helpers/ostream.hpp b/libuavcan/include/uavcan/helpers/ostream.hpp
index 60edcc010f..e75f9d22fe 100644
--- a/libuavcan/include/uavcan/helpers/ostream.hpp
+++ b/libuavcan/include/uavcan/helpers/ostream.hpp
@@ -18,7 +18,7 @@ namespace uavcan
  * Usage:
  *      OStream::instance() << "Hello world!" << OStream::endl;
  */
-class OStream : uavcan::Noncopyable
+class UAVCAN_EXPORT OStream : uavcan::Noncopyable
 {
     OStream() { }