diff --git a/libsrc/core/python_ngcore.hpp b/libsrc/core/python_ngcore.hpp
index 831bb56b..44bf0362 100644
--- a/libsrc/core/python_ngcore.hpp
+++ b/libsrc/core/python_ngcore.hpp
@@ -215,7 +215,7 @@ namespace ngcore
     }
 
   template<typename ARCHIVE>
-  class PyArchive : public ARCHIVE
+  class NGCORE_API_EXPORT PyArchive : public ARCHIVE
   {
   private:
     pybind11::list lst;