diff --git a/contrib/measurement/hdf5/include/ecal/measurement/hdf5/writer.h b/contrib/measurement/hdf5/include/ecal/measurement/hdf5/writer.h
index 8e20c2036d..3d11703a47 100644
--- a/contrib/measurement/hdf5/include/ecal/measurement/hdf5/writer.h
+++ b/contrib/measurement/hdf5/include/ecal/measurement/hdf5/writer.h
@@ -39,7 +39,7 @@ namespace eCAL
     {
       namespace hdf5
       {
-        class WriterImpl;
+        struct WriterImpl;
 
         /**
          * @brief Hdf5 based Writer implementation