diff --git a/gen_serialization.mako.hpp b/gen_serialization.mako.hpp
index b4d9568..df29dd4 100644
--- a/gen_serialization.mako.hpp
+++ b/gen_serialization.mako.hpp
@@ -63,7 +63,7 @@
         {
             a(${t});
         }
-        catch (Exception &e)
+        catch (const Exception &e)
         {
             // Ignore any exceptions, property value stays default
         }